mirror of https://gitee.com/openkylin/linux.git
12081 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Huang Ying
|
61b639723b |
mm, swap: use page-cluster as max window of VMA based swap readahead
When the VMA based swap readahead was introduced, a new knob
/sys/kernel/mm/swap/vma_ra_max_order
was added as the max window of VMA swap readahead. This is to make it
possible to use different max window for VMA based readahead and
original physical readahead. But Minchan Kim pointed out that this will
cause a regression because setting page-cluster sysctl to zero cannot
disable swap readahead with the change.
To fix the regression, the page-cluster sysctl is used as the max window
of both the VMA based swap readahead and original physical swap
readahead. If more fine grained control is needed in the future, more
knobs can be added as the subordinate knobs of the page-cluster sysctl.
The vma_ra_max_order knob is deleted. Because the knob was introduced
in v4.14-rc1, and this patch is targeting being merged before v4.14
releasing, there should be no existing users of this newly added ABI.
Link: http://lkml.kernel.org/r/20171011070847.16003-1-ying.huang@intel.com
Fixes:
|
|
|
Will Deacon
|
a7b100953a |
mm: page_vma_mapped: ensure pmd is loaded with READ_ONCE outside of lock
Loading the pmd without holding the pmd_lock exposes us to races with
concurrent updaters of the page tables but, worse still, it also allows
the compiler to cache the pmd value in a register and reuse it later on,
even if we've performed a READ_ONCE in between and seen a more recent
value.
In the case of page_vma_mapped_walk, this leads to the following crash
when the pmd loaded for the initial pmd_trans_huge check is all zeroes
and a subsequent valid table entry is loaded by check_pmd. We then
proceed into map_pte, but the compiler re-uses the zero entry inside
pte_offset_map, resulting in a junk pointer being installed in
pvmw->pte:
PC is at check_pte+0x20/0x170
LR is at page_vma_mapped_walk+0x2e0/0x540
[...]
Process doio (pid: 2463, stack limit = 0xffff00000f2e8000)
Call trace:
check_pte+0x20/0x170
page_vma_mapped_walk+0x2e0/0x540
page_mkclean_one+0xac/0x278
rmap_walk_file+0xf0/0x238
rmap_walk+0x64/0xa0
page_mkclean+0x90/0xa8
clear_page_dirty_for_io+0x84/0x2a8
mpage_submit_page+0x34/0x98
mpage_process_page_bufs+0x164/0x170
mpage_prepare_extent_to_map+0x134/0x2b8
ext4_writepages+0x484/0xe30
do_writepages+0x44/0xe8
__filemap_fdatawrite_range+0xbc/0x110
file_write_and_wait_range+0x48/0xd8
ext4_sync_file+0x80/0x4b8
vfs_fsync_range+0x64/0xc0
SyS_msync+0x194/0x1e8
This patch fixes the problem by ensuring that READ_ONCE is used before
the initial checks on the pmd, and this value is subsequently used when
checking whether or not the pmd is present. pmd_check is removed and
the pmd_present check is inlined directly.
Link: http://lkml.kernel.org/r/1507222630-5839-1-git-send-email-will.deacon@arm.com
Fixes:
|
|
|
Johannes Weiner
|
b8c8a338f7 |
Revert "vmalloc: back off when the current task is killed"
This reverts commits |
|
|
Boris Brezillon
|
ef4650144e |
mm/cma.c: take __GFP_NOWARN into account in cma_alloc()
cma_alloc() unconditionally prints an INFO message when the CMA allocation fails. Make this message conditional on the non-presence of __GFP_NOWARN in gfp_mask. This patch aims at removing INFO messages that are displayed when the VC4 driver tries to allocate buffer objects. From the driver perspective an allocation failure is acceptable, and the driver can possibly do something to make following allocation succeed (like flushing the VC4 internal cache). Link: http://lkml.kernel.org/r/20171004125447.15195-1-boris.brezillon@free-electrons.com Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Acked-by: Laura Abbott <labbott@redhat.com> Cc: Jaewon Kim <jaewon31.kim@samsung.com> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Eric Anholt <eric@anholt.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Zi Yan
|
af0db981f3 |
mm: remove unnecessary WARN_ONCE in page_vma_mapped_walk().
A non present pmd entry can appear after pmd_lock is taken in
page_vma_mapped_walk(), even if THP migration is not enabled. The
WARN_ONCE is unnecessary.
Link: http://lkml.kernel.org/r/20171003142606.12324-1-zi.yan@sent.com
Fixes:
|
|
|
Andrey Ryabinin
|
de55c8b251 |
mm/mempolicy: fix NUMA_INTERLEAVE_HIT counter
Commit |
|
|
Yang Shi
|
c02c300932 |
mm/madvise.c: add description for MADV_WIPEONFORK and MADV_KEEPONFORK
mm/madvise.c has a brief description about all MADV_ flags. Add a description for the newly added MADV_WIPEONFORK and MADV_KEEPONFORK. Although man page has the similar information, but it'd better to keep the consistent with other flags. Link: http://lkml.kernel.org/r/1506117328-88228-1-git-send-email-yang.s@alibaba-inc.com Signed-off-by: Yang Shi <yang.s@alibaba-inc.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Mark Hairgrove
|
e20d103b6c |
mm/migrate: fix indexing bug (off by one) and avoid out of bound access
Index was incremented before last use and thus the second array could
dereference to an invalid address (not mentioning the fact that it did
not properly clear the entry we intended to clear).
Link: http://lkml.kernel.org/r/1506973525-16491-1-git-send-email-jglisse@redhat.com
Fixes:
|
|
|
Michael DeGuzis
|
b14d595aa2 |
mm/huge_memory.c: fixup grammar in comment
This patch fixes up some grammar and spelling in the information block for huge_memory.c. Signed-off-by: Michael DeGuzis <mdeguzis@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> |
|
|
Eric Dumazet
|
9f1c2674b3 |
net: memcontrol: defer call to mem_cgroup_sk_alloc()
Instead of calling mem_cgroup_sk_alloc() from BH context,
it is better to call it from inet_csk_accept() in process context.
Not only this removes code in mem_cgroup_sk_alloc(), but it also
fixes a bug since listener might have been dismantled and css_get()
might cause a use-after-free.
Fixes:
|
|
|
Yafang Shao
|
94af584692 |
writeback: schedule periodic writeback with sysctl
After disable periodic writeback by writing 0 to dirty_writeback_centisecs, the handler wb_workfn() will not be entered again until the dirty background limit reaches or sync syscall is executed or no enough free memory available or vmscan is triggered. So the periodic writeback can't be enabled by writing a non-zero value to dirty_writeback_centisecs. As it can be disabled by sysctl, it should be able to enable by sysctl as well. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
|
|
Matthew Auld
|
703321b60b |
mm/shmem: introduce shmem_file_setup_with_mnt
We are planning to use our own tmpfs mnt in i915 in place of the shm_mnt, such that we can control the mount options, in particular huge=, which we require to support huge-gtt-pages. So rather than roll our own version of __shmem_file_setup, it would be preferred if we could just give shmem our mnt, and let it do the rest. Signed-off-by: Matthew Auld <matthew.auld@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Acked-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171006145041.21673-2-matthew.auld@intel.com Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20171006221833.32439-1-chris@chris-wilson.co.uk |
|
|
Jens Axboe
|
775d3a35dc |
backing-dev: kill unused pdflush_proc_obsolete()
After commit
|
|
|
Nicolas Pitre
|
438a506180 |
percpu: don't forget to free the temporary struct pcpu_alloc_info
Unlike the SMP case, the !SMP case does not free the memory for struct pcpu_alloc_info allocated in setup_per_cpu_areas(). And to give it a chance of being reused by the page allocator later, align it to a page boundary just like its size. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Dennis Zhou <dennisszhou@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> |
|
|
YASUAKI ISHIMATSU
|
d09b0137d2 |
mm/memory_hotplug: define find_{smallest|biggest}_section_pfn as unsigned long
find_{smallest|biggest}_section_pfn()s find the smallest/biggest section
and return the pfn of the section. But the functions are defined as int.
So the functions always return 0x00000000 - 0xffffffff. It means if
memory address is over 16TB, the functions does not work correctly.
To handle 64 bit value, the patch defines
find_{smallest|biggest}_section_pfn() as unsigned long.
Fixes:
|
|
|
YASUAKI ISHIMATSU
|
1dd2bfc868 |
mm/memory_hotplug: change pfn_to_section_nr/section_nr_to_pfn macro to inline function
pfn_to_section_nr() and section_nr_to_pfn() are defined as macro.
pfn_to_section_nr() has no issue even if it is defined as macro. But
section_nr_to_pfn() has overflow issue if sec is defined as int.
section_nr_to_pfn() just shifts sec by PFN_SECTION_SHIFT. If sec is
defined as unsigned long, section_nr_to_pfn() returns pfn as 64 bit value.
But if sec is defined as int, section_nr_to_pfn() returns pfn as 32 bit
value.
__remove_section() calculates start_pfn using section_nr_to_pfn() and
scn_nr defined as int. So if hot-removed memory address is over 16TB,
overflow issue occurs and section_nr_to_pfn() does not calculate correct
pfn.
To make callers use proper arg, the patch changes the macros to inline
functions.
Fixes:
|
|
|
Michal Hocko
|
9b6e63cbf8 |
mm, page_alloc: add scheduling point to memmap_init_zone
memmap_init_zone gets a pfn range to initialize and it can be really
large resulting in a soft lockup on non-preemptible kernels
NMI watchdog: BUG: soft lockup - CPU#31 stuck for 23s! [kworker/u642:5:1720]
[...]
task: ffff88ecd7e902c0 ti: ffff88eca4e50000 task.ti: ffff88eca4e50000
RIP: move_pfn_range_to_zone+0x185/0x1d0
[...]
Call Trace:
devm_memremap_pages+0x2c7/0x430
pmem_attach_disk+0x2fd/0x3f0 [nd_pmem]
nvdimm_bus_probe+0x64/0x110 [libnvdimm]
driver_probe_device+0x1f7/0x420
bus_for_each_drv+0x52/0x80
__device_attach+0xb0/0x130
bus_probe_device+0x87/0xa0
device_add+0x3fc/0x5f0
nd_async_device_register+0xe/0x40 [libnvdimm]
async_run_entry_fn+0x43/0x150
process_one_work+0x14e/0x410
worker_thread+0x116/0x490
kthread+0xc7/0xe0
ret_from_fork+0x3f/0x70
Fix this by adding a scheduling point once per page block.
Link: http://lkml.kernel.org/r/20170918121410.24466-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Michal Hocko
|
f64ac5e6e3 |
mm, memory_hotplug: add scheduling point to __add_pages
Patch series "mm, memory_hotplug: fix few soft lockups in memory
hotadd".
Johannes has noticed few soft lockups when adding a large nvdimm device.
All of them were caused by a long loop without any explicit cond_resched
which is a problem for !PREEMPT kernels.
The fix is quite straightforward. Just make sure that cond_resched gets
called from time to time.
This patch (of 3):
__add_pages gets a pfn range to add and there is no upper bound for a
single call. This is usually a memory block aligned size for the
regular memory hotplug - smaller sizes are usual for memory balloning
drivers, or the whole NUMA node for physical memory online. There is no
explicit scheduling point in that code path though.
This can lead to long latencies while __add_pages is executed and we
have even seen a soft lockup report during nvdimm initialization with
!PREEMPT kernel
NMI watchdog: BUG: soft lockup - CPU#11 stuck for 23s! [kworker/u641:3:832]
[...]
Workqueue: events_unbound async_run_entry_fn
task: ffff881809270f40 ti: ffff881809274000 task.ti: ffff881809274000
RIP: _raw_spin_unlock_irqrestore+0x11/0x20
RSP: 0018:ffff881809277b10 EFLAGS: 00000286
[...]
Call Trace:
sparse_add_one_section+0x13d/0x18e
__add_pages+0x10a/0x1d0
arch_add_memory+0x4a/0xc0
devm_memremap_pages+0x29d/0x430
pmem_attach_disk+0x2fd/0x3f0 [nd_pmem]
nvdimm_bus_probe+0x64/0x110 [libnvdimm]
driver_probe_device+0x1f7/0x420
bus_for_each_drv+0x52/0x80
__device_attach+0xb0/0x130
bus_probe_device+0x87/0xa0
device_add+0x3fc/0x5f0
nd_async_device_register+0xe/0x40 [libnvdimm]
async_run_entry_fn+0x43/0x150
process_one_work+0x14e/0x410
worker_thread+0x116/0x490
kthread+0xc7/0xe0
ret_from_fork+0x3f/0x70
DWARF2 unwinder stuck at ret_from_fork+0x3f/0x70
Fix this by adding cond_resched once per each memory section in the
given pfn range. Each section is constant amount of work which itself
is not too expensive but many of them will just add up.
Link: http://lkml.kernel.org/r/20170918121410.24466-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Johannes Weiner
|
f80c7dab95 |
mm: memcontrol: use vmalloc fallback for large kmem memcg arrays
For quick per-memcg indexing, slab caches and list_lru structures maintain linear arrays of descriptors. As the number of concurrent memory cgroups in the system goes up, this requires large contiguous allocations (8k cgroups = order-5, 16k cgroups = order-6 etc.) for every existing slab cache and list_lru, which can easily fail on loaded systems. E.g.: mkdir: page allocation failure: order:5, mode:0x14040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null) CPU: 1 PID: 6399 Comm: mkdir Not tainted 4.13.0-mm1-00065-g720bbe532b7c-dirty #481 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014 Call Trace: ? __alloc_pages_direct_compact+0x4c/0x110 __alloc_pages_nodemask+0xf50/0x1430 alloc_pages_current+0x60/0xc0 kmalloc_order_trace+0x29/0x1b0 __kmalloc+0x1f4/0x320 memcg_update_all_list_lrus+0xca/0x2e0 mem_cgroup_css_alloc+0x612/0x670 cgroup_apply_control_enable+0x19e/0x360 cgroup_mkdir+0x322/0x490 kernfs_iop_mkdir+0x55/0x80 vfs_mkdir+0xd0/0x120 SyS_mkdirat+0x6c/0xe0 SyS_mkdir+0x14/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Mem-Info: active_anon:2965 inactive_anon:19 isolated_anon:0 active_file:100270 inactive_file:98846 isolated_file:0 unevictable:0 dirty:0 writeback:0 unstable:0 slab_reclaimable:7328 slab_unreclaimable:16402 mapped:771 shmem:52 pagetables:278 bounce:0 free:13718 free_pcp:0 free_cma:0 This output is from an artificial reproducer, but we have repeatedly observed order-7 failures in production in the Facebook fleet. These systems become useless as they cannot run more jobs, even though there is plenty of memory to allocate 128 individual pages. Use kvmalloc and kvzalloc to fall back to vmalloc space if these arrays prove too large for allocating them physically contiguous. Link: http://lkml.kernel.org/r/20170918184919.20644-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Josef Bacik <jbacik@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Reza Arbab
|
7d790d2da3 |
mm/device-public-memory: fix edge case in _vm_normal_page()
With device public pages at the end of my memory space, I'm getting
output from _vm_normal_page():
BUG: Bad page map in process migrate_pages pte:c0800001ffff0d06 pmd:f95d3000
addr:00007fff89330000 vm_flags:00100073 anon_vma:c0000000fa899320 mapping: (null) index:7fff8933
file: (null) fault: (null) mmap: (null) readpage: (null)
CPU: 0 PID: 13963 Comm: migrate_pages Tainted: P B OE 4.14.0-rc1-wip #155
Call Trace:
dump_stack+0xb0/0xf4 (unreliable)
print_bad_pte+0x28c/0x340
_vm_normal_page+0xc0/0x140
zap_pte_range+0x664/0xc10
unmap_page_range+0x318/0x670
unmap_vmas+0x74/0xe0
exit_mmap+0xe8/0x1f0
mmput+0xac/0x1f0
do_exit+0x348/0xcd0
do_group_exit+0x5c/0xf0
SyS_exit_group+0x1c/0x20
system_call+0x58/0x6c
The pfn causing this is the very last one. Correct the bounds check
accordingly.
Fixes:
|
|
|
Shaohua Li
|
9625456cc7 |
mm: fix data corruption caused by lazyfree page
MADV_FREE clears pte dirty bit and then marks the page lazyfree (clear
SwapBacked). There is no lock to prevent the page is added to swap
cache between these two steps by page reclaim. If page reclaim finds
such page, it will simply add the page to swap cache without pageout the
page to swap because the page is marked as clean. Next time, page fault
will read data from the swap slot which doesn't have the original data,
so we have a data corruption. To fix issue, we mark the page dirty and
pageout the page.
However, we shouldn't dirty all pages which is clean and in swap cache.
swapin page is swap cache and clean too. So we only dirty page which is
added into swap cache in page reclaim, which shouldn't be swapin page.
As Minchan suggested, simply dirty the page in add_to_swap can do the
job.
Fixes:
|
|
|
Shaohua Li
|
24c92eb7dc |
mm: avoid marking swap cached page as lazyfree
MADV_FREE clears pte dirty bit and then marks the page lazyfree (clear
SwapBacked). There is no lock to prevent the page is added to swap
cache between these two steps by page reclaim. Page reclaim could add
the page to swap cache and unmap the page. After page reclaim, the page
is added back to lru. At that time, we probably start draining per-cpu
pagevec and mark the page lazyfree. So the page could be in a state
with SwapBacked cleared and PG_swapcache set. Next time there is a
refault in the virtual address, do_swap_page can find the page from swap
cache but the page has PageSwapCache false because SwapBacked isn't set,
so do_swap_page will bail out and do nothing. The task will keep
running into fault handler.
Fixes:
|
|
|
Jeff Layton
|
f4e222c56c |
mm: have filemap_check_and_advance_wb_err clear AS_EIO/AS_ENOSPC
Eryu noticed that he could sometimes get a leftover error reported when it shouldn't be on fsync with ext2 and non-journalled ext4. The problem is that writeback_single_inode still uses filemap_fdatawait. That picks up a previously set AS_EIO flag, which would ordinarily have been cleared before. Since we're mostly using this function as a replacement for filemap_check_errors, have filemap_check_and_advance_wb_err clear AS_EIO and AS_ENOSPC when reporting an error. That should allow the new function to better emulate the behavior of the old with respect to these flags. Link: http://lkml.kernel.org/r/20170922133331.28812-1-jlayton@kernel.org Signed-off-by: Jeff Layton <jlayton@redhat.com> Reported-by: Eryu Guan <eguan@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Christophe Leroy
|
a872eb2131 |
mm: fix RODATA_TEST failure "rodata_test: test data was not read only"
On powerpc, RODATA_TEST fails with message the following messages: Freeing unused kernel memory: 528K rodata_test: test data was not read only This is because GCC allocates it to .data section: c0695034 g O .data 00000004 rodata_test_data Since commit |
|
|
Arnd Bergmann
|
57148a64e8 |
mm: meminit: mark init_reserved_page as __meminit
The function is called from __meminit context and calls other __meminit
functions but isn't it self mark as such today:
WARNING: vmlinux.o(.text.unlikely+0x4516): Section mismatch in reference from the function init_reserved_page() to the function .meminit.text:early_pfn_to_nid()
The function init_reserved_page() references the function __meminit early_pfn_to_nid().
This is often because init_reserved_page lacks a __meminit annotation or the annotation of early_pfn_to_nid is wrong.
On most compilers, we don't notice this because the function gets
inlined all the time. Adding __meminit here fixes the harmless warning
for the old versions and is generally the correct annotation.
Link: http://lkml.kernel.org/r/20170915193149.901180-1-arnd@arndb.de
Fixes:
|
|
|
Vitaly Wool
|
3552935742 |
z3fold: fix stale list handling
Fix the situation when clear_bit() is called for page->private before the page pointer is actually assigned. While at it, remove work_busy() check because it is costly and does not give 100% guarantee anyway. Signed-off-by: Vitaly Wool <vitalywool@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: <Oleksiy.Avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Davidlohr Bueso
|
6818600ff0 |
mm,compaction: serialize waitqueue_active() checks (for real)
Andrea brought to my attention that the L->{L,S} guarantees are
completely bogus for this case. I was looking at the diagram, from the
offending commit, when that _is_ the race, we had the load reordered
already.
What we need is at least S->L semantics, thus simply use
wq_has_sleeper() to serialize the call for good.
Link: http://lkml.kernel.org/r/20170914175313.GB811@linux-80c1.suse
Fixes:
|
|
|
Jérôme Glisse
|
3f2eb0287e |
mm/memcg: avoid page count check for zone device
Fix for 4.14, zone device page always have an elevated refcount of one and thus page count sanity check in uncharge_page() is inappropriate for them. [mhocko@suse.com: nano-optimize VM_BUG_ON in uncharge_page] Link: http://lkml.kernel.org/r/20170914190011.5217-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Evgeny Baskakov <ebaskakov@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
72f0184c8a |
mm, memcg: remove hotplug locking from try_charge
The following lockdep splat has been noticed during LTP testing
======================================================
WARNING: possible circular locking dependency detected
4.13.0-rc3-next-20170807 #12 Not tainted
------------------------------------------------------
a.out/4771 is trying to acquire lock:
(cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffff812b4668>] drain_all_stock.part.35+0x18/0x140
but task is already holding lock:
(&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&mm->mmap_sem){++++++}:
lock_acquire+0xc9/0x230
__might_fault+0x70/0xa0
_copy_to_user+0x23/0x70
filldir+0xa7/0x110
xfs_dir2_sf_getdents.isra.10+0x20c/0x2c0 [xfs]
xfs_readdir+0x1fa/0x2c0 [xfs]
xfs_file_readdir+0x30/0x40 [xfs]
iterate_dir+0x17a/0x1a0
SyS_getdents+0xb0/0x160
entry_SYSCALL_64_fastpath+0x1f/0xbe
-> #2 (&type->i_mutex_dir_key#3){++++++}:
lock_acquire+0xc9/0x230
down_read+0x51/0xb0
lookup_slow+0xde/0x210
walk_component+0x160/0x250
link_path_walk+0x1a6/0x610
path_openat+0xe4/0xd50
do_filp_open+0x91/0x100
file_open_name+0xf5/0x130
filp_open+0x33/0x50
kernel_read_file_from_path+0x39/0x80
_request_firmware+0x39f/0x880
request_firmware_direct+0x37/0x50
request_microcode_fw+0x64/0xe0
reload_store+0xf7/0x180
dev_attr_store+0x18/0x30
sysfs_kf_write+0x44/0x60
kernfs_fop_write+0x113/0x1a0
__vfs_write+0x37/0x170
vfs_write+0xc7/0x1c0
SyS_write+0x58/0xc0
do_syscall_64+0x6c/0x1f0
return_from_SYSCALL_64+0x0/0x7a
-> #1 (microcode_mutex){+.+.+.}:
lock_acquire+0xc9/0x230
__mutex_lock+0x88/0x960
mutex_lock_nested+0x1b/0x20
microcode_init+0xbb/0x208
do_one_initcall+0x51/0x1a9
kernel_init_freeable+0x208/0x2a7
kernel_init+0xe/0x104
ret_from_fork+0x2a/0x40
-> #0 (cpu_hotplug_lock.rw_sem){++++++}:
__lock_acquire+0x153c/0x1550
lock_acquire+0xc9/0x230
cpus_read_lock+0x4b/0x90
drain_all_stock.part.35+0x18/0x140
try_charge+0x3ab/0x6e0
mem_cgroup_try_charge+0x7f/0x2c0
shmem_getpage_gfp+0x25f/0x1050
shmem_fault+0x96/0x200
__do_fault+0x1e/0xa0
__handle_mm_fault+0x9c3/0xe00
handle_mm_fault+0x16e/0x380
__do_page_fault+0x24a/0x530
do_page_fault+0x30/0x80
page_fault+0x28/0x30
other info that might help us debug this:
Chain exists of:
cpu_hotplug_lock.rw_sem --> &type->i_mutex_dir_key#3 --> &mm->mmap_sem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&mm->mmap_sem);
lock(&type->i_mutex_dir_key#3);
lock(&mm->mmap_sem);
lock(cpu_hotplug_lock.rw_sem);
*** DEADLOCK ***
2 locks held by a.out/4771:
#0: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530
#1: (percpu_charge_mutex){+.+...}, at: [<ffffffff812b4c97>] try_charge+0x397/0x6e0
The problem is very similar to the one fixed by commit
|
|
|
Michal Hocko
|
4d4bbd8526 |
mm, oom_reaper: skip mm structs with mmu notifiers
Andrea has noticed that the oom_reaper doesn't invalidate the range via
mmu notifiers (mmu_notifier_invalidate_range_start/end) and that can
corrupt the memory of the kvm guest for example.
tlb_flush_mmu_tlbonly already invokes mmu notifiers but that is not
sufficient as per Andrea:
"mmu_notifier_invalidate_range cannot be used in replacement of
mmu_notifier_invalidate_range_start/end. For KVM
mmu_notifier_invalidate_range is a noop and rightfully so. A MMU
notifier implementation has to implement either ->invalidate_range
method or the invalidate_range_start/end methods, not both. And if you
implement invalidate_range_start/end like KVM is forced to do, calling
mmu_notifier_invalidate_range in common code is a noop for KVM.
For those MMU notifiers that can get away only implementing
->invalidate_range, the ->invalidate_range is implicitly called by
mmu_notifier_invalidate_range_end(). And only those secondary MMUs
that share the same pagetable with the primary MMU (like AMD iommuv2)
can get away only implementing ->invalidate_range"
As the callback is allowed to sleep and the implementation is out of
hand of the MM it is safer to simply bail out if there is an mmu
notifier registered. In order to not fail too early make the
mm_has_notifiers check under the oom_lock and have a little nap before
failing to give the current oom victim some more time to exit.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170913113427.2291-1-mhocko@kernel.org
Fixes:
|
|
|
Vitaly Wool
|
d5567c9df1 |
z3fold: fix potential race in z3fold_reclaim_page
It is possible that on a (partially) unsuccessful page reclaim, kref_put() called in z3fold_reclaim_page() does not yield page release, but the page is released shortly afterwards by another thread. Then z3fold_reclaim_page() would try to list_add() that (released) page again which is obviously a bug. To avoid that, spin_lock() has to be taken earlier, before the kref_put() call mentioned earlier. Link: http://lkml.kernel.org/r/20170913162937.bfff21c7d12b12a5f47639fd@gmail.com Signed-off-by: Vitaly Wool <vitalywool@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: <Oleksiy.Avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Alexandru Moise
|
19bfbe22f5 |
mm, hugetlb, soft_offline: save compound page order before page migration
This fixes a bug in madvise() where if you'd try to soft offline a
hugepage via madvise(), while walking the address range you'd end up,
using the wrong page offset due to attempting to get the compound order
of a former but presently not compound page, due to dissolving the huge
page (since commit c3114a84f7f9: "mm: hugetlb: soft-offline: dissolve
source hugepage after successful migration").
As a result I ended up with all my free pages except one being offlined.
Link: http://lkml.kernel.org/r/20170912204306.GA12053@gmail.com
Fixes:
|
|
|
Kirill Tkhai
|
4b22927f0c |
ksm: fix unlocked iteration over vmas in cmp_and_merge_page()
In this place mm is unlocked, so vmas or list may change. Down read
mmap_sem to protect them from modifications.
Link: http://lkml.kernel.org/r/150512788393.10691.8868381099691121308.stgit@localhost.localdomain
Fixes:
|
|
|
Jens Axboe
|
0ab29fd0ac |
writeback: pass in '0' for nr_pages writeback in laptop mode
Laptop mode really wants to writeback the number of dirty pages and inodes. Instead of calculating this in the caller, just pass in 0 and let wakeup_flusher_threads() handle it. Use the new wakeup_flusher_threads_bdi() instead of rolling our own. Acked-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Chris Mason <clm@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
|
|
Jens Axboe
|
47410d88f6 |
writeback: remove 'range_cyclic' argument for wb_start_writeback()
All the callers pass in 'true' for range_cyclic, so kill the argument. Signed-off-by: Jens Axboe <axboe@kernel.dk> |
|
|
Jens Axboe
|
9ba4b2dfaf |
fs: kill 'nr_pages' argument from wakeup_flusher_threads()
Everybody is passing in 0 now, let's get rid of the argument. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
|
|
Dennis Zhou
|
1fa4df3e68 |
percpu: fix iteration to prevent skipping over block
The iterator functions pcpu_next_md_free_region and pcpu_next_fit_region use the block offset to determine if they have checked the area in the prior iteration. However, this causes an issue when the block offset is greater than subsequent block contig hints. If within the iterator it moves to check subsequent blocks, it may fail in the second predicate due to the block offset not being cleared. Thus, this causes the allocator to skip over blocks leading to false failures when allocating from the reserved chunk. While this happens in the general case as well, it will only fail if it cannot allocate a new chunk. This patch resets the block offset to 0 to pass the second predicate when checking subseqent blocks within the iterator function. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Reported-and-tested-by: Luis Henriques <lhenriques@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org> |
|
|
Dennis Zhou
|
2e08d20d77 |
percpu: fix starting offset for chunk statistics traversal
This patch fixes the starting offset used when scanning chunks to compute the chunk statistics. The value start_offset (and end_offset) are managed in bytes while the traversal occurs over bits. Thus for the reserved and dynamic chunk, it may incorrectly skip over the initial allocations. Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> |
|
|
Lukas Czerner
|
332391a993 |
fs: Fix page cache inconsistency when mixing buffered and AIO DIO
Currently when mixing buffered reads and asynchronous direct writes it is possible to end up with the situation where we have stale data in the page cache while the new data is already written to disk. This is permanent until the affected pages are flushed away. Despite the fact that mixing buffered and direct IO is ill-advised it does pose a thread for a data integrity, is unexpected and should be fixed. Fix this by deferring completion of asynchronous direct writes to a process context in the case that there are mapped pages to be found in the inode. Later before the completion in dio_complete() invalidate the pages in question. This ensures that after the completion the pages in the written area are either unmapped, or populated with up-to-date data. Also do the same for the iomap case which uses iomap_dio_complete() instead. This has a side effect of deferring the completion to a process context for every AIO DIO that happens on inode that has pages mapped. However since the consensus is that this is ill-advised practice the performance implication should not be a problem. This was based on proposal from Jeff Moyer, thanks! Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
|
|
Linus Torvalds
|
e253d98f5b |
Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull nowait read support from Al Viro: "Support IOCB_NOWAIT for buffered reads and block devices" * 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: block_dev: support RFW_NOWAIT on block device nodes fs: support RWF_NOWAIT for buffered reads fs: support IOCB_NOWAIT in generic_file_buffered_read fs: pass iocb to do_generic_file_read |
|
|
Linus Torvalds
|
581bfce969 |
Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more set_fs removal from Al Viro:
"Christoph's 'use kernel_read and friends rather than open-coding
set_fs()' series"
* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: unexport vfs_readv and vfs_writev
fs: unexport vfs_read and vfs_write
fs: unexport __vfs_read/__vfs_write
lustre: switch to kernel_write
gadget/f_mass_storage: stop messing with the address limit
mconsole: switch to kernel_read
btrfs: switch write_buf to kernel_write
net/9p: switch p9_fd_read to kernel_write
mm/nommu: switch do_mmap_private to kernel_read
serial2002: switch serial2002_tty_write to kernel_{read/write}
fs: make the buf argument to __kernel_write a void pointer
fs: fix kernel_write prototype
fs: fix kernel_read prototype
fs: move kernel_read to fs/read_write.c
fs: move kernel_write to fs/read_write.c
autofs4: switch autofs4_write to __kernel_write
ashmem: switch to ->read_iter
|
|
|
Linus Torvalds
|
7a95bdb092 |
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton: "A few leftovers" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm, page_owner: skip unnecessary stack_trace entries arm64: stacktrace: avoid listing stacktrace functions in stacktrace mm: treewide: remove GFP_TEMPORARY allocation flag IB/mlx4: fix sprintf format warning fscache: fix fscache_objlist_show format processing lib/test_bitmap.c: use ULL suffix for 64-bit constants procfs: remove unused variable drivers/media/cec/cec-adap.c: fix build with gcc-4.4.4 idr: remove WARN_ON_ONCE() when trying to replace negative ID |
|
|
Tim Chen
|
11a19c7b09 |
sched/wait: Introduce wakeup boomark in wake_up_page_bit
Now that we have added breaks in the wait queue scan and allow bookmark on scan position, we put this logic in the wake_up_page_bit function. We can have very long page wait list in large system where multiple pages share the same wait list. We break the wake up walk here to allow other cpus a chance to access the list, and not to disable the interrupts when traversing the list for too long. This reduces the interrupt and rescheduling latency, and excessive page wait queue lock hold time. [ v2: Remove bookmark_wake_function ] Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Prakash Gupta
|
5f48f0bd4e |
mm, page_owner: skip unnecessary stack_trace entries
The page_owner stacktrace always begin as follows: [<ffffff987bfd48f4>] save_stack+0x40/0xc8 [<ffffff987bfd4da8>] __set_page_owner+0x3c/0x6c These two entries do not provide any useful information and limits the available stacktrace depth. The page_owner stacktrace was skipping caller function from stack entries but this was missed with commit |
|
|
Michal Hocko
|
0ee931c4e3 |
mm: treewide: remove GFP_TEMPORARY allocation flag
GFP_TEMPORARY was introduced by commit
|
|
|
Kirill A. Shutemov
|
5b65c4677a |
mm, x86/mm: Fix performance regression in get_user_pages_fast()
The 0-day test bot found a performance regression that was tracked down to
switching x86 to the generic get_user_pages_fast() implementation:
http://lkml.kernel.org/r/20170710024020.GA26389@yexl-desktop
The regression was caused by the fact that we now use local_irq_save() +
local_irq_restore() in get_user_pages_fast() to disable interrupts.
In x86 implementation local_irq_disable() + local_irq_enable() was used.
The fix is to make get_user_pages_fast() use local_irq_disable(),
leaving local_irq_save() for __get_user_pages_fast() that can be called
with interrupts disabled.
Numbers for pinning a gigabyte of memory, one page a time, 20 repeats:
Before: Average: 14.91 ms, stddev: 0.45 ms
After: Average: 10.76 ms, stddev: 0.18 ms
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: linux-mm@kvack.org
Fixes:
|
|
|
Christophe JAILLET
|
0b045bd1c1 |
mm/backing-dev.c: fix an error handling path in 'cgwb_create()'
If the 'kmalloc' fails, we must go through the existing error handling
path.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Fixes:
|
|
|
Davidlohr Bueso
|
fa90b2fd30 |
mem/memcg: cache rightmost node
Such that we can optimize __mem_cgroup_largest_soft_limit_node(). The only overhead is the extra footprint for the cached pointer, but this should not be an issue for mem_cgroup_tree_per_node. [dave@stgolabs.net: brain fart #2] Link: http://lkml.kernel.org/r/20170731160114.GE21328@linux-80c1.suse Link: http://lkml.kernel.org/r/20170719014603.19029-17-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Davidlohr Bueso
|
f808c13fd3 |
lib/interval_tree: fast overlap detection
Allow interval trees to quickly check for overlaps to avoid unnecesary tree lookups in interval_tree_iter_first(). As of this patch, all interval tree flavors will require using a 'rb_root_cached' such that we can have the leftmost node easily available. While most users will make use of this feature, those with special functions (in addition to the generic insert, delete, search calls) will avoid using the cached option as they can do funky things with insertions -- for example, vma_interval_tree_insert_after(). [jglisse@redhat.com: fix deadlock from typo vm_lock_anon_vma()] Link: http://lkml.kernel.org/r/20170808225719.20723-1-jglisse@redhat.com Link: http://lkml.kernel.org/r/20170719014603.19029-12-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: David Airlie <airlied@linux.ie> Cc: Jason Wang <jasowang@redhat.com> Cc: Christian Benvenuti <benve@cisco.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Alexey Dobriyan
|
9b130ad5bb |
treewide: make "nr_cpu_ids" unsigned
First, number of CPUs can't be negative number. Second, different signnnedness leads to suboptimal code in the following cases: 1) kmalloc(nr_cpu_ids * sizeof(X)); "int" has to be sign extended to size_t. 2) while (loff_t *pos < nr_cpu_ids) MOVSXD is 1 byte longed than the same MOV. Other cases exist as well. Basically compiler is told that nr_cpu_ids can't be negative which can't be deduced if it is "int". Code savings on allyesconfig kernel: -3KB add/remove: 0/0 grow/shrink: 25/264 up/down: 261/-3631 (-3370) function old new delta coretemp_cpu_online 450 512 +62 rcu_init_one 1234 1272 +38 pci_device_probe 374 399 +25 ... pgdat_reclaimable_pages 628 556 -72 select_fallback_rq 446 369 -77 task_numa_find_cpu 1923 1807 -116 Link: http://lkml.kernel.org/r/20170819114959.GA30580@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Anshuman Khandual
|
149728e913 |
mm/mempolicy.c: remove BUG_ON() checks for VMA inside mpol_misplaced()
VMA and its address bounds checks are too late in this function. They must have been verified earlier in the page fault sequence. Hence just remove them. Link: http://lkml.kernel.org/r/20170901130137.7617-1-khandual@linux.vnet.ibm.com Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
David Rientjes
|
b6b1fd2a6b |
mm/swapfile.c: fix swapon frontswap_map memory leak on error
Free frontswap_map if an error is encountered before enable_swap_info(). Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> [4.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Darrick J. Wong
|
8606a1a94d |
mm: kvfree the swap cluster info if the swap file is unsatisfactory
If initializing a small swap file fails because the swap file has a
problem (holes, etc.) then we need to free the cluster info as part of
cleanup. Unfortunately a previous patch changed the code to use kvzalloc
but did not change all the vfree calls to use kvfree.
Found by running generic/357 from xfstests.
Link: http://lkml.kernel.org/r/20170831233515.GR3775@magnolia
Fixes:
|
|
|
Tetsuo Handa
|
f19360f015 |
mm/page_alloc.c: apply gfp_allowed_mask before the first allocation attempt
We are by error initializing alloc_flags before gfp_allowed_mask is
applied. This could cause problems after pm_restrict_gfp_mask() is called
during suspend operation. Apply gfp_allowed_mask before initializing
alloc_flags so that the first allocation attempt uses correct flags.
Link: http://lkml.kernel.org/r/201709020016.ADJ21342.OFLJHOOSMFVtFQ@I-love.SAKURA.ne.jp
Fixes:
|
|
|
Michal Hocko
|
b4ccec41af |
mm/sparse.c: fix typo in online_mem_sections
online_mem_sections() accidentally marks online only the first section
in the given range. This is a typo which hasn't been noticed because I
haven't tested large 2GB blocks previously. All users of
pfn_to_online_page would get confused on the the rest of the pfn range
in the block.
All we need to fix this is to use iterator (pfn) rather than start_pfn.
Link: http://lkml.kernel.org/r/20170904112210.3401-1-mhocko@kernel.org
Fixes:
|
|
|
Laurent Dufour
|
de0c799bba |
mm/memory.c: fix mem_cgroup_oom_disable() call missing
Seen while reading the code, in handle_mm_fault(), in the case
arch_vma_access_permitted() is failing the call to
mem_cgroup_oom_disable() is not made.
To fix that, move the call to mem_cgroup_oom_enable() after calling
arch_vma_access_permitted() as it should not have entered the memcg OOM.
Link: http://lkml.kernel.org/r/1504625439-31313-1-git-send-email-ldufour@linux.vnet.ibm.com
Fixes:
|
|
|
Roman Gushchin
|
475d0487a2 |
mm: memcontrol: use per-cpu stocks for socket memory uncharging
We've noticed a quite noticeable performance overhead on some hosts with significant network traffic when socket memory accounting is enabled. Perf top shows that socket memory uncharging path is hot: 2.13% [kernel] [k] page_counter_cancel 1.14% [kernel] [k] __sk_mem_reduce_allocated 1.14% [kernel] [k] _raw_spin_lock 0.87% [kernel] [k] _raw_spin_lock_irqsave 0.84% [kernel] [k] tcp_ack 0.84% [kernel] [k] ixgbe_poll 0.83% < workload > 0.82% [kernel] [k] enqueue_entity 0.68% [kernel] [k] __fget 0.68% [kernel] [k] tcp_delack_timer_handler 0.67% [kernel] [k] __schedule 0.60% < workload > 0.59% [kernel] [k] __inet6_lookup_established 0.55% [kernel] [k] __switch_to 0.55% [kernel] [k] menu_select 0.54% libc-2.20.so [.] __memcpy_avx_unaligned To address this issue, the existing per-cpu stock infrastructure can be used. refill_stock() can be called from mem_cgroup_uncharge_skmem() to move charge to a per-cpu stock instead of calling atomic page_counter_uncharge(). To prevent the uncontrolled growth of per-cpu stocks, refill_stock() will explicitly drain the cached charge, if the cached value exceeds CHARGE_BATCH. This allows significantly optimize the load: 1.21% [kernel] [k] _raw_spin_lock 1.01% [kernel] [k] ixgbe_poll 0.92% [kernel] [k] _raw_spin_lock_irqsave 0.90% [kernel] [k] enqueue_entity 0.86% [kernel] [k] tcp_ack 0.85% < workload > 0.74% perf-11120.map [.] 0x000000000061bf24 0.73% [kernel] [k] __schedule 0.67% [kernel] [k] __fget 0.63% [kernel] [k] __inet6_lookup_established 0.62% [kernel] [k] menu_select 0.59% < workload > 0.59% [kernel] [k] __switch_to 0.57% libc-2.20.so [.] __memcpy_avx_unaligned Link: http://lkml.kernel.org/r/20170829100150.4580-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Shakeel Butt
|
3a77d21480 |
mm: fadvise: avoid fadvise for fs without backing device
The fadvise() manpage is silent on fadvise()'s effect on memory-based filesystems (shmem, hugetlbfs & ramfs) and pseudo file systems (procfs, sysfs, kernfs). The current implementaion of fadvise is mostly a noop for such filesystems except for FADV_DONTNEED which will trigger expensive remote LRU cache draining. This patch makes the noop of fadvise() on such file systems very explicit. However this change has two side effects for ramfs and one for tmpfs. First fadvise(FADV_DONTNEED) could remove the unmapped clean zero'ed pages of ramfs (allocated through read, readahead & read fault) and tmpfs (allocated through read fault). Also fadvise(FADV_WILLNEED) could create such clean zero'ed pages for ramfs. This change removes those possibilities. One of our generic libraries does fadvise(FADV_DONTNEED). Recently we observed high latency in fadvise() and noticed that the users have started using tmpfs files and the latency was due to expensive remote LRU cache draining. For normal tmpfs files (have data written on them), fadvise(FADV_DONTNEED) will always trigger the unneeded remote cache draining. Link: http://lkml.kernel.org/r/20170818011023.181465-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Matthias Kaehlcke
|
3eb95feac1 |
mm/zsmalloc.c: change stat type parameter to int
zs_stat_inc/dec/get() uses enum zs_stat_type for the stat type, however some callers pass an enum fullness_group value. Change the type to int to reflect the actual use of the functions and get rid of 'enum-conversion' warnings Link: http://lkml.kernel.org/r/20170731175000.56538-1-mka@chromium.org Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Doug Anderson <dianders@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Joonsoo Kim
|
9472f23c9e |
mm/mlock.c: use page_zone() instead of page_zone_id()
page_zone_id() is a specialized function to compare the zone for the pages that are within the section range. If the section of the pages are different, page_zone_id() can be different even if their zone is the same. This wrong usage doesn't cause any actual problem since __munlock_pagevec_fill() would be called again with failed index. However, it's better to use more appropriate function here. Link: http://lkml.kernel.org/r/1503559211-10259-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Kemi Wang
|
638032224e |
mm: consider the number in local CPUs when reading NUMA stats
To avoid deviation, the per cpu number of NUMA stats in vm_numa_stat_diff[] is included when a user *reads* the NUMA stats. Since NUMA stats does not be read by users frequently, and kernel does not need it to make a decision, it will not be a problem to make the readers more expensive. Link: http://lkml.kernel.org/r/1503568801-21305-4-git-send-email-kemi.wang@intel.com Signed-off-by: Kemi Wang <kemi.wang@intel.com> Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Ying Huang <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Kemi Wang
|
1d90ca897c |
mm: update NUMA counter threshold size
There is significant overhead in cache bouncing caused by zone counters (NUMA associated counters) update in parallel in multi-threaded page allocation (suggested by Dave Hansen). This patch updates NUMA counter threshold to a fixed size of MAX_U16 - 2, as a small threshold greatly increases the update frequency of the global counter from local per cpu counter(suggested by Ying Huang). The rationality is that these statistics counters don't affect the kernel's decision, unlike other VM counters, so it's not a problem to use a large threshold. With this patchset, we see 31.3% drop of CPU cycles(537-->369) for per single page allocation and reclaim on Jesper's page_bench03 benchmark. Benchmark provided by Jesper D Brouer(increase loop times to 10000000): https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/ bench Threshold CPU cycles Throughput(88 threads) 32 799 241760478 64 640 301628829 125 537 358906028 <==> system by default (base) 256 468 412397590 512 428 450550704 4096 399 482520943 20000 394 489009617 30000 395 488017817 65533 369(-31.3%) 521661345(+45.3%) <==> with this patchset N/A 342(-36.3%) 562900157(+56.8%) <==> disable zone_statistics Link: http://lkml.kernel.org/r/1503568801-21305-3-git-send-email-kemi.wang@intel.com Signed-off-by: Kemi Wang <kemi.wang@intel.com> Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Suggested-by: Dave Hansen <dave.hansen@intel.com> Suggested-by: Ying Huang <ying.huang@intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Christopher Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Tim Chen <tim.c.chen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Kemi Wang
|
3a321d2a3d |
mm: change the call sites of numa statistics items
Patch series "Separate NUMA statistics from zone statistics", v2. Each page allocation updates a set of per-zone statistics with a call to zone_statistics(). As discussed in 2017 MM summit, these are a substantial source of overhead in the page allocator and are very rarely consumed. This significant overhead in cache bouncing caused by zone counters (NUMA associated counters) update in parallel in multi-threaded page allocation (pointed out by Dave Hansen). A link to the MM summit slides: http://people.netfilter.org/hawk/presentations/MM-summit2017/MM-summit2017-JesperBrouer.pdf To mitigate this overhead, this patchset separates NUMA statistics from zone statistics framework, and update NUMA counter threshold to a fixed size of MAX_U16 - 2, as a small threshold greatly increases the update frequency of the global counter from local per cpu counter (suggested by Ying Huang). The rationality is that these statistics counters don't need to be read often, unlike other VM counters, so it's not a problem to use a large threshold and make readers more expensive. With this patchset, we see 31.3% drop of CPU cycles(537-->369, see below) for per single page allocation and reclaim on Jesper's page_bench03 benchmark. Meanwhile, this patchset keeps the same style of virtual memory statistics with little end-user-visible effects (only move the numa stats to show behind zone page stats, see the first patch for details). I did an experiment of single page allocation and reclaim concurrently using Jesper's page_bench03 benchmark on a 2-Socket Broadwell-based server (88 processors with 126G memory) with different size of threshold of pcp counter. Benchmark provided by Jesper D Brouer(increase loop times to 10000000): https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/bench Threshold CPU cycles Throughput(88 threads) 32 799 241760478 64 640 301628829 125 537 358906028 <==> system by default 256 468 412397590 512 428 450550704 4096 399 482520943 20000 394 489009617 30000 395 488017817 65533 369(-31.3%) 521661345(+45.3%) <==> with this patchset N/A 342(-36.3%) 562900157(+56.8%) <==> disable zone_statistics This patch (of 3): In this patch, NUMA statistics is separated from zone statistics framework, all the call sites of NUMA stats are changed to use numa-stats-specific functions, it does not have any functionality change except that the number of NUMA stats is shown behind zone page stats when users *read* the zone info. E.g. cat /proc/zoneinfo ***Base*** ***With this patch*** nr_free_pages 3976 nr_free_pages 3976 nr_zone_inactive_anon 0 nr_zone_inactive_anon 0 nr_zone_active_anon 0 nr_zone_active_anon 0 nr_zone_inactive_file 0 nr_zone_inactive_file 0 nr_zone_active_file 0 nr_zone_active_file 0 nr_zone_unevictable 0 nr_zone_unevictable 0 nr_zone_write_pending 0 nr_zone_write_pending 0 nr_mlock 0 nr_mlock 0 nr_page_table_pages 0 nr_page_table_pages 0 nr_kernel_stack 0 nr_kernel_stack 0 nr_bounce 0 nr_bounce 0 nr_zspages 0 nr_zspages 0 numa_hit 0 *nr_free_cma 0* numa_miss 0 numa_hit 0 numa_foreign 0 numa_miss 0 numa_interleave 0 numa_foreign 0 numa_local 0 numa_interleave 0 numa_other 0 numa_local 0 *nr_free_cma 0* numa_other 0 ... ... vm stats threshold: 10 vm stats threshold: 10 ... ... The next patch updates the numa stats counter size and threshold. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1503568801-21305-2-git-send-email-kemi.wang@intel.com Signed-off-by: Kemi Wang <kemi.wang@intel.com> Reported-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Ying Huang <ying.huang@intel.com> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Anshuman Khandual
|
fde26bed58 |
mm/memory.c: remove reduntant check for write access
Flags argument has been copied into vmf.flags and it is not changed in between. Hence a single write access check can be used for both PUD and PMD. Link: http://lkml.kernel.org/r/20170823082839.1812-1-khandual@linux.vnet.ibm.com Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Laurent Dufour
|
98c70baad4 |
mm: remove useless vma parameter to offset_il_node
While reading the code I found that offset_il_node() has a vm_area_struct pointer parameter which is unused. Link: http://lkml.kernel.org/r/1502899755-23146-1-git-send-email-ldufour@linux.vnet.ibm.com Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
6b368cd4a4 |
mm/hmm: avoid bloating arch that do not make use of HMM
This moves all new code including new page migration helper behind kernel Kconfig option so that there is no codee bloat for arch or user that do not want to use HMM or any of its associated features. arm allyesconfig (without all the patchset, then with and this patch): text data bss dec hex filename 83721896 46511131 27582964 157815991 96814b7 ../without/vmlinux 83722364 46511131 27582964 157816459 968168b vmlinux [jglisse@redhat.com: struct hmm is only use by HMM mirror functionality] Link: http://lkml.kernel.org/r/20170825213133.27286-1-jglisse@redhat.com [sfr@canb.auug.org.au: fix build (arm multi_v7_defconfig)] Link: http://lkml.kernel.org/r/20170828181849.323ab81b@canb.auug.org.au Link: http://lkml.kernel.org/r/20170818032858.7447-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
d3df0a4233 |
mm/hmm: add new helper to hotplug CDM memory region
Unlike unaddressable memory, coherent device memory has a real resource associated with it on the system (as CPU can address it). Add a new helper to hotplug such memory within the HMM framework. Link: http://lkml.kernel.org/r/20170817000548.32038-20-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Balbir Singh <bsingharora@gmail.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
df6ad69838 |
mm/device-public-memory: device memory cache coherent with CPU
Platform with advance system bus (like CAPI or CCIX) allow device memory to be accessible from CPU in a cache coherent fashion. Add a new type of ZONE_DEVICE to represent such memory. The use case are the same as for the un-addressable device memory but without all the corners cases. Link: http://lkml.kernel.org/r/20170817000548.32038-19-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
8315ada7f0 |
mm/migrate: allow migrate_vma() to alloc new page on empty entry
This allows callers of migrate_vma() to allocate new page for empty CPU page table entry (pte_none or back by zero page). This is only for anonymous memory and it won't allow new page to be instanced if the userfaultfd is armed. This is useful to device driver that want to migrate a range of virtual address and would rather allocate new memory than having to fault later on. Link: http://lkml.kernel.org/r/20170817000548.32038-18-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
a5430dda8a |
mm/migrate: support un-addressable ZONE_DEVICE page in migration
Allow to unmap and restore special swap entry of un-addressable ZONE_DEVICE memory. Link: http://lkml.kernel.org/r/20170817000548.32038-17-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
8c3328f1f3 |
mm/migrate: migrate_vma() unmap page from vma while collecting pages
Common case for migration of virtual address range is page are map only once inside the vma in which migration is taking place. Because we already walk the CPU page table for that range we can directly do the unmap there and setup special migration swap entry. Link: http://lkml.kernel.org/r/20170817000548.32038-16-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
8763cb45ab |
mm/migrate: new memory migration helper for use with device memory
This patch add a new memory migration helpers, which migrate memory backing a range of virtual address of a process to different memory (which can be allocated through special allocator). It differs from numa migration by working on a range of virtual address and thus by doing migration in chunk that can be large enough to use DMA engine or special copy offloading engine. Expected users are any one with heterogeneous memory where different memory have different characteristics (latency, bandwidth, ...). As an example IBM platform with CAPI bus can make use of this feature to migrate between regular memory and CAPI device memory. New CPU architecture with a pool of high performance memory not manage as cache but presented as regular memory (while being faster and with lower latency than DDR) will also be prime user of this patch. Migration to private device memory will be useful for device that have large pool of such like GPU, NVidia plans to use HMM for that. Link: http://lkml.kernel.org/r/20170817000548.32038-15-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
2916ecc0f9 |
mm/migrate: new migrate mode MIGRATE_SYNC_NO_COPY
Introduce a new migration mode that allow to offload the copy to a device
DMA engine. This changes the workflow of migration and not all
address_space migratepage callback can support this.
This is intended to be use by migrate_vma() which itself is use for thing
like HMM (see include/linux/hmm.h).
No additional per-filesystem migratepage testing is needed. I disables
MIGRATE_SYNC_NO_COPY in all problematic migratepage() callback and i
added comment in those to explain why (part of this patch). The commit
message is unclear it should say that any callback that wish to support
this new mode need to be aware of the difference in the migration flow
from other mode.
Some of these callbacks do extra locking while copying (aio, zsmalloc,
balloon, ...) and for DMA to be effective you want to copy multiple
pages in one DMA operations. But in the problematic case you can not
easily hold the extra lock accross multiple call to this callback.
Usual flow is:
For each page {
1 - lock page
2 - call migratepage() callback
3 - (extra locking in some migratepage() callback)
4 - migrate page state (freeze refcount, update page cache, buffer
head, ...)
5 - copy page
6 - (unlock any extra lock of migratepage() callback)
7 - return from migratepage() callback
8 - unlock page
}
The new mode MIGRATE_SYNC_NO_COPY:
1 - lock multiple pages
For each page {
2 - call migratepage() callback
3 - abort in all problematic migratepage() callback
4 - migrate page state (freeze refcount, update page cache, buffer
head, ...)
} // finished all calls to migratepage() callback
5 - DMA copy multiple pages
6 - unlock all the pages
To support MIGRATE_SYNC_NO_COPY in the problematic case we would need a
new callback migratepages() (for instance) that deals with multiple
pages in one transaction.
Because the problematic cases are not important for current usage I did
not wanted to complexify this patchset even more for no good reason.
Link: http://lkml.kernel.org/r/20170817000548.32038-14-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Nellans <dnellans@nvidia.com>
Cc: Evgeny Baskakov <ebaskakov@nvidia.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mark Hairgrove <mhairgrove@nvidia.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Sherry Cheung <SCheung@nvidia.com>
Cc: Subhash Gutti <sgutti@nvidia.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Bob Liu <liubo95@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Jérôme Glisse
|
858b54dabf |
mm/hmm/devmem: dummy HMM device for ZONE_DEVICE memory
This introduce a dummy HMM device class so device driver can use it to create hmm_device for the sole purpose of registering device memory. It is useful to device driver that want to manage multiple physical device memory under same struct device umbrella. Link: http://lkml.kernel.org/r/20170817000548.32038-13-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
4ef589dc9b |
mm/hmm/devmem: device memory hotplug using ZONE_DEVICE
This introduce a simple struct and associated helpers for device driver to use when hotpluging un-addressable device memory as ZONE_DEVICE. It will find a unuse physical address range and trigger memory hotplug for it which allocates and initialize struct page for the device memory. Device driver should use this helper during device initialization to hotplug the device memory. It should only need to remove the memory once the device is going offline (shutdown or hotremove). There should not be any userspace API to hotplug memory expect maybe for host device driver to allow to add more memory to a guest device driver. Device's memory is manage by the device driver and HMM only provides helpers to that effect. Link: http://lkml.kernel.org/r/20170817000548.32038-12-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
c733a82874 |
mm/memcontrol: support MEMORY_DEVICE_PRIVATE
HMM pages (private or public device pages) are ZONE_DEVICE page and thus need special handling when it comes to lru or refcount. This patch make sure that memcontrol properly handle those when it face them. Those pages are use like regular pages in a process address space either as anonymous page or as file back page. So from memcg point of view we want to handle them like regular page for now at least. Link: http://lkml.kernel.org/r/20170817000548.32038-11-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
a9d5adeeb4 |
mm/memcontrol: allow to uncharge page without using page->lru field
HMM pages (private or public device pages) are ZONE_DEVICE page and thus you can not use page->lru fields of those pages. This patch re-arrange the uncharge to allow single page to be uncharge without modifying the lru field of the struct page. There is no change to memcontrol logic, it is the same as it was before this patch. Link: http://lkml.kernel.org/r/20170817000548.32038-10-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
7b2d55d2c8 |
mm/ZONE_DEVICE: special case put_page() for device private pages
A ZONE_DEVICE page that reach a refcount of 1 is free ie no longer have any user. For device private pages this is important to catch and thus we need to special case put_page() for this. Link: http://lkml.kernel.org/r/20170817000548.32038-9-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
5042db43cc |
mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddressable memory
HMM (heterogeneous memory management) need struct page to support migration from system main memory to device memory. Reasons for HMM and migration to device memory is explained with HMM core patch. This patch deals with device memory that is un-addressable memory (ie CPU can not access it). Hence we do not want those struct page to be manage like regular memory. That is why we extend ZONE_DEVICE to support different types of memory. A persistent memory type is define for existing user of ZONE_DEVICE and a new device un-addressable type is added for the un-addressable memory type. There is a clear separation between what is expected from each memory type and existing user of ZONE_DEVICE are un-affected by new requirement and new use of the un-addressable type. All specific code path are protect with test against the memory type. Because memory is un-addressable we use a new special swap type for when a page is migrated to device memory (this reduces the number of maximum swap file). The main two additions beside memory type to ZONE_DEVICE is two callbacks. First one, page_free() is call whenever page refcount reach 1 (which means the page is free as ZONE_DEVICE page never reach a refcount of 0). This allow device driver to manage its memory and associated struct page. The second callback page_fault() happens when there is a CPU access to an address that is back by a device page (which are un-addressable by the CPU). This callback is responsible to migrate the page back to system main memory. Device driver can not block migration back to system memory, HMM make sure that such page can not be pin into device memory. If device is in some error condition and can not migrate memory back then a CPU page fault to device memory should end with SIGBUS. [arnd@arndb.de: fix warning] Link: http://lkml.kernel.org/r/20170823133213.712917-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170817000548.32038-8-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
74eee180b9 |
mm/hmm/mirror: device page fault handler
This handles page fault on behalf of device driver, unlike handle_mm_fault() it does not trigger migration back to system memory for device memory. Link: http://lkml.kernel.org/r/20170817000548.32038-6-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
da4c3c735e |
mm/hmm/mirror: helper to snapshot CPU page table
This does not use existing page table walker because we want to share same code for our page fault handler. Link: http://lkml.kernel.org/r/20170817000548.32038-5-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
c0b124054f |
mm/hmm/mirror: mirror process address space on device with HMM helpers
This is a heterogeneous memory management (HMM) process address space mirroring. In a nutshell this provide an API to mirror process address space on a device. This boils down to keeping CPU and device page table synchronize (we assume that both device and CPU are cache coherent like PCIe device can be). This patch provide a simple API for device driver to achieve address space mirroring thus avoiding each device driver to grow its own CPU page table walker and its own CPU page table synchronization mechanism. This is useful for NVidia GPU >= Pascal, Mellanox IB >= mlx5 and more hardware in the future. [jglisse@redhat.com: fix hmm for "mmu_notifier kill invalidate_page callback"] Link: http://lkml.kernel.org/r/20170830231955.GD9445@redhat.com Link: http://lkml.kernel.org/r/20170817000548.32038-4-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
133ff0eac9 |
mm/hmm: heterogeneous memory management (HMM for short)
HMM provides 3 separate types of functionality:
- Mirroring: synchronize CPU page table and device page table
- Device memory: allocating struct page for device memory
- Migration: migrating regular memory to device memory
This patch introduces some common helpers and definitions to all of
those 3 functionality.
Link: http://lkml.kernel.org/r/20170817000548.32038-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Signed-off-by: Sherry Cheung <SCheung@nvidia.com>
Signed-off-by: Subhash Gutti <sgutti@nvidia.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Nellans <dnellans@nvidia.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Bob Liu <liubo95@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Naoya Horiguchi
|
8135d8926c |
mm: memory_hotplug: memory hotremove supports thp migration
This patch enables thp migration for memory hotremove. Link: http://lkml.kernel.org/r/20170717193955.20207-11-zi.yan@sent.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Naoya Horiguchi
|
e8db67eb0d |
mm: migrate: move_pages() supports thp migration
This patch enables thp migration for move_pages(2). Link: http://lkml.kernel.org/r/20170717193955.20207-10-zi.yan@sent.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Naoya Horiguchi
|
c863379849 |
mm: mempolicy: mbind and migrate_pages support thp migration
This patch enables thp migration for mbind(2) and migrate_pages(2). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Naoya Horiguchi
|
ab6e3d0939 |
mm: soft-dirty: keep soft-dirty bits over thp migration
Soft dirty bit is designed to keep tracked over page migration. This patch makes it work in the same manner for thp migration too. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Zi Yan
|
84c3fc4e9c |
mm: thp: check pmd migration entry in common path
When THP migration is being used, memory management code needs to handle pmd migration entries properly. This patch uses !pmd_present() or is_swap_pmd() (depending on whether pmd_none() needs separate code or not) to check pmd migration entries at the places where a pmd entry is present. Since pmd-related code uses split_huge_page(), split_huge_pmd(), pmd_trans_huge(), pmd_trans_unstable(), or pmd_none_or_trans_huge_or_clear_bad(), this patch: 1. adds pmd migration entry split code in split_huge_pmd(), 2. takes care of pmd migration entries whenever pmd_trans_huge() is present, 3. makes pmd_none_or_trans_huge_or_clear_bad() pmd migration entry aware. Since split_huge_page() uses split_huge_pmd() and pmd_trans_unstable() is equivalent to pmd_none_or_trans_huge_or_clear_bad(), we do not change them. Until this commit, a pmd entry should be: 1. pointing to a pte page, 2. is_swap_pmd(), 3. pmd_trans_huge(), 4. pmd_devmap(), or 5. pmd_none(). Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Zi Yan
|
616b837153 |
mm: thp: enable thp migration in generic path
Add thp migration's core code, including conversions between a PMD entry and a swap entry, setting PMD migration entry, removing PMD migration entry, and waiting on PMD migration entries. This patch makes it possible to support thp migration. If you fail to allocate a destination page as a thp, you just split the source thp as we do now, and then enter the normal page migration. If you succeed to allocate destination thp, you enter thp migration. Subsequent patches actually enable thp migration for each caller of page migration by allowing its get_new_page() callback to allocate thps. [zi.yan@cs.rutgers.edu: fix gcc-4.9.0 -Wmissing-braces warning] Link: http://lkml.kernel.org/r/A0ABA698-7486-46C3-B209-E95A9048B22C@cs.rutgers.edu [akpm@linux-foundation.org: fix x86_64 allnoconfig warning] Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Naoya Horiguchi
|
9c670ea379 |
mm: thp: introduce CONFIG_ARCH_ENABLE_THP_MIGRATION
Introduce CONFIG_ARCH_ENABLE_THP_MIGRATION to limit thp migration functionality to x86_64, which should be safer at the first step. Link: http://lkml.kernel.org/r/20170717193955.20207-5-zi.yan@sent.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Naoya Horiguchi
|
b5ff8161e3 |
mm: thp: introduce separate TTU flag for thp freezing
TTU_MIGRATION is used to convert pte into migration entry until thp
split completes. This behavior conflicts with thp migration added later
patches, so let's introduce a new TTU flag specifically for freezing.
try_to_unmap() is used both for thp split (via freeze_page()) and page
migration (via __unmap_and_move()). In freeze_page(), ttu_flag given
for head page is like below (assuming anonymous thp):
(TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS | TTU_RMAP_LOCKED | \
TTU_MIGRATION | TTU_SPLIT_HUGE_PMD)
and ttu_flag given for tail pages is:
(TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS | TTU_RMAP_LOCKED | \
TTU_MIGRATION)
__unmap_and_move() calls try_to_unmap() with ttu_flag:
(TTU_MIGRATION | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS)
Now I'm trying to insert a branch for thp migration at the top of
try_to_unmap_one() like below
static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
unsigned long address, void *arg)
{
...
/* PMD-mapped THP migration entry */
if (!pvmw.pte && (flags & TTU_MIGRATION)) {
if (!PageAnon(page))
continue;
set_pmd_migration_entry(&pvmw, page);
continue;
}
...
}
so try_to_unmap() for tail pages called by thp split can go into thp
migration code path (which converts *pmd* into migration entry), while
the expectation is to freeze thp (which converts *pte* into migration
entry.)
I detected this failure as a "bad page state" error in a testcase where
split_huge_page() is called from queue_pages_pte_range().
Link: http://lkml.kernel.org/r/20170717193955.20207-4-zi.yan@sent.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Nellans <dnellans@nvidia.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Naoya Horiguchi
|
88aaa2a1d7 |
mm: mempolicy: add queue_pages_required()
Patch series "mm: page migration enhancement for thp", v9. Motivations: 1. THP migration becomes important in the upcoming heterogeneous memory systems. As David Nellans from NVIDIA pointed out from other threads (http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1349227.html), future GPUs or other accelerators will have their memory managed by operating systems. Moving data into and out of these memory nodes efficiently is critical to applications that use GPUs or other accelerators. Existing page migration only supports base pages, which has a very low memory bandwidth utilization. My experiments (see below) show THP migration can migrate pages more efficiently. 2. Base page migration vs THP migration throughput. Here are cross-socket page migration results from calling move_pages() syscall: In x86_64, a Intel two-socket E5-2640v3 box, - single 4KB base page migration takes 62.47 us, using 0.06 GB/s BW, - single 2MB THP migration takes 658.54 us, using 2.97 GB/s BW, - 512 4KB base page migration takes 1987.38 us, using 0.98 GB/s BW. In ppc64, a two-socket Power8 box, - single 64KB base page migration takes 49.3 us, using 1.24 GB/s BW, - single 16MB THP migration takes 2202.17 us, using 7.10 GB/s BW, - 256 64KB base page migration takes 2543.65 us, using 6.14 GB/s BW. THP migration can give us 3x and 1.15x throughput over base page migration in x86_64 and ppc64 respectivley. You can test it out by using the code here: https://github.com/x-y-z/thp-migration-bench 3. Existing page migration splits THP before migration and cannot guarantee the migrated pages are still contiguous. Contiguity is always what GPUs and accelerators look for. Without THP migration, khugepaged needs to do extra work to reassemble the migrated pages back to THPs. This patch (of 10): Introduce a separate check routine related to MPOL_MF_INVERT flag. This patch just does cleanup, no behavioral change. Link: http://lkml.kernel.org/r/20170717193955.20207-2-zi.yan@sent.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Linus Torvalds
|
a0725ab0c7 |
Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
"This is the first pull request for 4.14, containing most of the code
changes. It's a quiet series this round, which I think we needed after
the churn of the last few series. This contains:
- Fix for a registration race in loop, from Anton Volkov.
- Overflow complaint fix from Arnd for DAC960.
- Series of drbd changes from the usual suspects.
- Conversion of the stec/skd driver to blk-mq. From Bart.
- A few BFQ improvements/fixes from Paolo.
- CFQ improvement from Ritesh, allowing idling for group idle.
- A few fixes found by Dan's smatch, courtesy of Dan.
- A warning fixup for a race between changing the IO scheduler and
device remova. From David Jeffery.
- A few nbd fixes from Josef.
- Support for cgroup info in blktrace, from Shaohua.
- Also from Shaohua, new features in the null_blk driver to allow it
to actually hold data, among other things.
- Various corner cases and error handling fixes from Weiping Zhang.
- Improvements to the IO stats tracking for blk-mq from me. Can
drastically improve performance for fast devices and/or big
machines.
- Series from Christoph removing bi_bdev as being needed for IO
submission, in preparation for nvme multipathing code.
- Series from Bart, including various cleanups and fixes for switch
fall through case complaints"
* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
kernfs: checking for IS_ERR() instead of NULL
drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
drbd: Fix allyesconfig build, fix recent commit
drbd: switch from kmalloc() to kmalloc_array()
drbd: abort drbd_start_resync if there is no connection
drbd: move global variables to drbd namespace and make some static
drbd: rename "usermode_helper" to "drbd_usermode_helper"
drbd: fix race between handshake and admin disconnect/down
drbd: fix potential deadlock when trying to detach during handshake
drbd: A single dot should be put into a sequence.
drbd: fix rmmod cleanup, remove _all_ debugfs entries
drbd: Use setup_timer() instead of init_timer() to simplify the code.
drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
drbd: new disk-option disable-write-same
drbd: Fix resource role for newly created resources in events2
drbd: mark symbols static where possible
drbd: Send P_NEG_ACK upon write error in protocol != C
drbd: add explicit plugging when submitting batches
drbd: change list_for_each_safe to while(list_first_entry_or_null)
drbd: introduce drbd_recv_header_maybe_unplug
...
|
|
|
Linus Torvalds
|
bac65d9d87 |
powerpc updates for 4.14
Nothing really major this release, despite quite a lot of activity. Just lots of
things all over the place.
Some things of note include:
- Access via perf to a new type of PMU (IMC) on Power9, which can count both
core events as well as nest unit events (Memory controller etc).
- Optimisations to the radix MMU TLB flushing, mostly to avoid unnecessary Page
Walk Cache (PWC) flushes when the structure of the tree is not changing.
- Reworks/cleanups of do_page_fault() to modernise it and bring it closer to
other architectures where possible.
- Rework of our page table walking so that THP updates only need to send IPIs
to CPUs where the affected mm has run, rather than all CPUs.
- The size of our vmalloc area is increased to 56T on 64-bit hash MMU systems.
This avoids problems with the percpu allocator on systems with very sparse
NUMA layouts.
- STRICT_KERNEL_RWX support on PPC32.
- A new sched domain topology for Power9, to capture the fact that pairs of
cores may share an L2 cache.
- Power9 support for VAS, which is a new mechanism for accessing coprocessors,
and initial support for using it with the NX compression accelerator.
- Major work on the instruction emulation support, adding support for many new
instructions, and reworking it so it can be used to implement the emulation
needed to fixup alignment faults.
- Support for guests under PowerVM to use the Power9 XIVE interrupt controller.
And probably that many things again that are almost as interesting, but I had to
keep the list short. Plus the usual fixes and cleanups as always.
Thanks to:
Alexey Kardashevskiy, Alistair Popple, Andreas Schwab, Aneesh Kumar K.V, Anju
T Sudhakar, Arvind Yadav, Balbir Singh, Benjamin Herrenschmidt, Bhumika Goyal,
Breno Leitao, Bryant G. Ly, Christophe Leroy, Cédric Le Goater, Dan Carpenter,
Dou Liyang, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff Levand,
Hannes Reinecke, Haren Myneni, Ivan Mikhaylov, John Allen, Julia Lawall, LABBE
Corentin, Laurentiu Tudor, Madhavan Srinivasan, Markus Elfring, Masahiro
Yamada, Matt Brown, Michael Neuling, Murilo Opsfelder Araujo, Nathan Fontenot,
Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Rashmica
Gupta, Rob Herring, Rui Teng, Sam Bobroff, Santosh Sivaraj, Scott Wood,
Shilpasri G Bhat, Sukadev Bhattiprolu, Suraj Jitindar Singh, Tobin C. Harding,
Victor Aoqui.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=UJtt
-----END PGP SIGNATURE-----
Merge tag 'powerpc-4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Nothing really major this release, despite quite a lot of activity.
Just lots of things all over the place.
Some things of note include:
- Access via perf to a new type of PMU (IMC) on Power9, which can
count both core events as well as nest unit events (Memory
controller etc).
- Optimisations to the radix MMU TLB flushing, mostly to avoid
unnecessary Page Walk Cache (PWC) flushes when the structure of the
tree is not changing.
- Reworks/cleanups of do_page_fault() to modernise it and bring it
closer to other architectures where possible.
- Rework of our page table walking so that THP updates only need to
send IPIs to CPUs where the affected mm has run, rather than all
CPUs.
- The size of our vmalloc area is increased to 56T on 64-bit hash MMU
systems. This avoids problems with the percpu allocator on systems
with very sparse NUMA layouts.
- STRICT_KERNEL_RWX support on PPC32.
- A new sched domain topology for Power9, to capture the fact that
pairs of cores may share an L2 cache.
- Power9 support for VAS, which is a new mechanism for accessing
coprocessors, and initial support for using it with the NX
compression accelerator.
- Major work on the instruction emulation support, adding support for
many new instructions, and reworking it so it can be used to
implement the emulation needed to fixup alignment faults.
- Support for guests under PowerVM to use the Power9 XIVE interrupt
controller.
And probably that many things again that are almost as interesting,
but I had to keep the list short. Plus the usual fixes and cleanups as
always.
Thanks to: Alexey Kardashevskiy, Alistair Popple, Andreas Schwab,
Aneesh Kumar K.V, Anju T Sudhakar, Arvind Yadav, Balbir Singh,
Benjamin Herrenschmidt, Bhumika Goyal, Breno Leitao, Bryant G. Ly,
Christophe Leroy, Cédric Le Goater, Dan Carpenter, Dou Liyang,
Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff Levand, Hannes
Reinecke, Haren Myneni, Ivan Mikhaylov, John Allen, Julia Lawall,
LABBE Corentin, Laurentiu Tudor, Madhavan Srinivasan, Markus Elfring,
Masahiro Yamada, Matt Brown, Michael Neuling, Murilo Opsfelder Araujo,
Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran,
Paul Mackerras, Rashmica Gupta, Rob Herring, Rui Teng, Sam Bobroff,
Santosh Sivaraj, Scott Wood, Shilpasri G Bhat, Sukadev Bhattiprolu,
Suraj Jitindar Singh, Tobin C. Harding, Victor Aoqui"
* tag 'powerpc-4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (321 commits)
powerpc/xive: Fix section __init warning
powerpc: Fix kernel crash in emulation of vector loads and stores
powerpc/xive: improve debugging macros
powerpc/xive: add XIVE Exploitation Mode to CAS
powerpc/xive: introduce H_INT_ESB hcall
powerpc/xive: add the HW IRQ number under xive_irq_data
powerpc/xive: introduce xive_esb_write()
powerpc/xive: rename xive_poke_esb() in xive_esb_read()
powerpc/xive: guest exploitation of the XIVE interrupt controller
powerpc/xive: introduce a common routine xive_queue_page_alloc()
powerpc/sstep: Avoid used uninitialized error
axonram: Return directly after a failed kzalloc() in axon_ram_probe()
axonram: Improve a size determination in axon_ram_probe()
axonram: Delete an error message for a failed memory allocation in axon_ram_probe()
powerpc/powernv/npu: Move tlb flush before launching ATSD
powerpc/macintosh: constify wf_sensor_ops structures
powerpc/iommu: Use permission-specific DEVICE_ATTR variants
powerpc/eeh: Delete an error out of memory message at init time
powerpc/mm: Use seq_putc() in two functions
macintosh: Convert to using %pOF instead of full_name
...
|
|
|
Linus Torvalds
|
608c1d3c17 |
Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
"Several notable changes this cycle:
- Thread mode was merged. This will be used for cgroup2 support for
CPU and possibly other controllers. Unfortunately, CPU controller
cgroup2 support didn't make this pull request but most contentions
have been resolved and the support is likely to be merged before
the next merge window.
- cgroup.stat now shows the number of descendant cgroups.
- cpuset now can enable the easier-to-configure v2 behavior on v1
hierarchy"
* 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
cpuset: Allow v2 behavior in v1 cgroup
cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup
cgroup: remove unneeded checks
cgroup: misc changes
cgroup: short-circuit cset_cgroup_from_root() on the default hierarchy
cgroup: re-use the parent pointer in cgroup_destroy_locked()
cgroup: add cgroup.stat interface with basic hierarchy stats
cgroup: implement hierarchy limits
cgroup: keep track of number of descent cgroups
cgroup: add comment to cgroup_enable_threaded()
cgroup: remove unnecessary empty check when enabling threaded mode
cgroup: update debug controller to print out thread mode information
cgroup: implement cgroup v2 thread support
cgroup: implement CSS_TASK_ITER_THREADED
cgroup: introduce cgroup->dom_cgrp and threaded css_set handling
cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS
cgroup: reorganize cgroup.procs / task write path
cgroup: replace css_set walking populated test with testing cgrp->nr_populated_csets
cgroup: distinguish local and children populated states
cgroup: remove now unused list_head @pending in cgroup_apply_cftypes()
...
|
|
|
Linus Torvalds
|
a7cbfd05f4 |
Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo: "A lot of changes for percpu this time around. percpu inherited the same area allocator from the original pre-virtual-address-mapped implementation. This was from the time when percpu allocator wasn't used all that much and the implementation was focused on simplicity, with the unfortunate computational complexity of O(number of areas allocated from the chunk) per alloc / free. With the increase in percpu usage, we're hitting cases where the lack of scalability is hurting. The most prominent one right now is bpf perpcu map creation / destruction which may allocate and free a lot of entries consecutively and it's likely that the problem will become more prominent in the future. To address the issue, Dennis replaced the area allocator with hinted bitmap allocator which is more consistent. While the new allocator does perform a bit worse in some cases, it outperforms the old allocator way more than an order of magnitude in other more common scenarios while staying mostly flat in CPU overhead and completely flat in memory consumption" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (27 commits) percpu: update header to contain bitmap allocator explanation. percpu: update pcpu_find_block_fit to use an iterator percpu: use metadata blocks to update the chunk contig hint percpu: update free path to take advantage of contig hints percpu: update alloc path to only scan if contig hints are broken percpu: keep track of the best offset for contig hints percpu: skip chunks if the alloc does not fit in the contig hint percpu: add first_bit to keep track of the first free in the bitmap percpu: introduce bitmap metadata blocks percpu: replace area map allocator with bitmap percpu: generalize bitmap (un)populated iterators percpu: increase minimum percpu allocation size and align first regions percpu: introduce nr_empty_pop_pages to help empty page accounting percpu: change the number of pages marked in the first_chunk pop bitmap percpu: combine percpu address checks percpu: modify base_addr to be region specific percpu: setup_first_chunk rename schunk/dchunk to chunk percpu: end chunk area maps page aligned for the populated bitmap percpu: unify allocation of schunk and dchunk percpu: setup_first_chunk remove dyn_size and consolidate logic ... |
|
|
Linus Torvalds
|
d34fc1adf0 |
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - various misc bits - DAX updates - OCFS2 - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (119 commits) mm,fork: introduce MADV_WIPEONFORK x86,mpx: make mpx depend on x86-64 to free up VMA flag mm: add /proc/pid/smaps_rollup mm: hugetlb: clear target sub-page last when clearing huge page mm: oom: let oom_reap_task and exit_mmap run concurrently swap: choose swap device according to numa node mm: replace TIF_MEMDIE checks by tsk_is_oom_victim mm, oom: do not rely on TIF_MEMDIE for memory reserves access z3fold: use per-cpu unbuddied lists mm, swap: don't use VMA based swap readahead if HDD is used as swap mm, swap: add sysfs interface for VMA based swap readahead mm, swap: VMA based swap readahead mm, swap: fix swap readahead marking mm, swap: add swap readahead hit statistics mm/vmalloc.c: don't reinvent the wheel but use existing llist API mm/vmstat.c: fix wrong comment selftests/memfd: add memfd_create hugetlbfs selftest mm/shmem: add hugetlbfs support to memfd_create() mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas() ... |
|
|
Rik van Riel
|
d2cd9ede6e |
mm,fork: introduce MADV_WIPEONFORK
Introduce MADV_WIPEONFORK semantics, which result in a VMA being empty
in the child process after fork. This differs from MADV_DONTFORK in one
important way.
If a child process accesses memory that was MADV_WIPEONFORK, it will get
zeroes. The address ranges are still valid, they are just empty.
If a child process accesses memory that was MADV_DONTFORK, it will get a
segmentation fault, since those address ranges are no longer valid in
the child after fork.
Since MADV_DONTFORK also seems to be used to allow very large programs
to fork in systems with strict memory overcommit restrictions, changing
the semantics of MADV_DONTFORK might break existing programs.
MADV_WIPEONFORK only works on private, anonymous VMAs.
The use case is libraries that store or cache information, and want to
know that they need to regenerate it in the child process after fork.
Examples of this would be:
- systemd/pulseaudio API checks (fail after fork) (replacing a getpid
check, which is too slow without a PID cache)
- PKCS#11 API reinitialization check (mandated by specification)
- glibc's upcoming PRNG (reseed after fork)
- OpenSSL PRNG (reseed after fork)
The security benefits of a forking server having a re-inialized PRNG in
every child process are pretty obvious. However, due to libraries
having all kinds of internal state, and programs getting compiled with
many different versions of each library, it is unreasonable to expect
calling programs to re-initialize everything manually after fork.
A further complication is the proliferation of clone flags, programs
bypassing glibc's functions to call clone directly, and programs calling
unshare, causing the glibc pthread_atfork hook to not get called.
It would be better to have the kernel take care of this automatically.
The patch also adds MADV_KEEPONFORK, to undo the effects of a prior
MADV_WIPEONFORK.
This is similar to the OpenBSD minherit syscall with MAP_INHERIT_ZERO:
https://man.openbsd.org/minherit.2
[akpm@linux-foundation.org: numerically order arch/parisc/include/uapi/asm/mman.h #defines]
Link: http://lkml.kernel.org/r/20170811212829.29186-3-riel@redhat.com
Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: Florian Weimer <fweimer@redhat.com>
Reported-by: Colm MacCártaigh <colm@allcosts.net>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Huang Ying
|
c79b57e462 |
mm: hugetlb: clear target sub-page last when clearing huge page
Huge page helps to reduce TLB miss rate, but it has higher cache footprint, sometimes this may cause some issue. For example, when clearing huge page on x86_64 platform, the cache footprint is 2M. But on a Xeon E5 v3 2699 CPU, there are 18 cores, 36 threads, and only 45M LLC (last level cache). That is, in average, there are 2.5M LLC for each core and 1.25M LLC for each thread. If the cache pressure is heavy when clearing the huge page, and we clear the huge page from the begin to the end, it is possible that the begin of huge page is evicted from the cache after we finishing clearing the end of the huge page. And it is possible for the application to access the begin of the huge page after clearing the huge page. To help the above situation, in this patch, when we clear a huge page, the order to clear sub-pages is changed. In quite some situation, we can get the address that the application will access after we clear the huge page, for example, in a page fault handler. Instead of clearing the huge page from begin to end, we will clear the sub-pages farthest from the the sub-page to access firstly, and clear the sub-page to access last. This will make the sub-page to access most cache-hot and sub-pages around it more cache-hot too. If we cannot know the address the application will access, the begin of the huge page is assumed to be the the address the application will access. With this patch, the throughput increases ~28.3% in vm-scalability anon-w-seq test case with 72 processes on a 2 socket Xeon E5 v3 2699 system (36 cores, 72 threads). The test case creates 72 processes, each process mmap a big anonymous memory area and writes to it from the begin to the end. For each process, other processes could be seen as other workload which generates heavy cache pressure. At the same time, the cache miss rate reduced from ~33.4% to ~31.7%, the IPC (instruction per cycle) increased from 0.56 to 0.74, and the time spent in user space is reduced ~7.9% Christopher Lameter suggests to clear bytes inside a sub-page from end to begin too. But tests show no visible performance difference in the tests. May because the size of page is small compared with the cache size. Thanks Andi Kleen to propose to use address to access to determine the order of sub-pages to clear. The hugetlbfs access address could be improved, will do that in another patch. [ying.huang@intel.com: improve readability of clear_huge_page()] Link: http://lkml.kernel.org/r/20170830051842.1397-1-ying.huang@intel.com Link: http://lkml.kernel.org/r/20170815014618.15842-1-ying.huang@intel.com Suggested-by: Andi Kleen <andi.kleen@intel.com> Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Jan Kara <jack@suse.cz> Reviewed-by: Michal Hocko <mhocko@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Nadia Yvette Chambers <nyc@holomorphy.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shaohua Li <shli@fb.com> Cc: Christopher Lameter <cl@linux.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Andrea Arcangeli
|
2129258024 |
mm: oom: let oom_reap_task and exit_mmap run concurrently
This is purely required because exit_aio() may block and exit_mmap() may
never start, if the oom_reap_task cannot start running on a mm with
mm_users == 0.
At the same time if the OOM reaper doesn't wait at all for the memory of
the current OOM candidate to be freed by exit_mmap->unmap_vmas, it would
generate a spurious OOM kill.
If it wasn't because of the exit_aio or similar blocking functions in
the last mmput, it would be enough to change the oom_reap_task() in the
case it finds mm_users == 0, to wait for a timeout or to wait for
__mmput to set MMF_OOM_SKIP itself, but it's not just exit_mmap the
problem here so the concurrency of exit_mmap and oom_reap_task is
apparently warranted.
It's a non standard runtime, exit_mmap() runs without mmap_sem, and
oom_reap_task runs with the mmap_sem for reading as usual (kind of
MADV_DONTNEED).
The race between the two is solved with a combination of
tsk_is_oom_victim() (serialized by task_lock) and MMF_OOM_SKIP
(serialized by a dummy down_write/up_write cycle on the same lines of
the ksm_exit method).
If the oom_reap_task() may be running concurrently during exit_mmap,
exit_mmap will wait it to finish in down_write (before taking down mm
structures that would make the oom_reap_task fail with use after free).
If exit_mmap comes first, oom_reap_task() will skip the mm if
MMF_OOM_SKIP is already set and in turn all memory is already freed and
furthermore the mm data structures may already have been taken down by
free_pgtables.
[aarcange@redhat.com: incremental one liner]
Link: http://lkml.kernel.org/r/20170726164319.GC29716@redhat.com
[rientjes@google.com: remove unused mmput_async]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708141733130.50317@chino.kir.corp.google.com
[aarcange@redhat.com: microoptimization]
Link: http://lkml.kernel.org/r/20170817171240.GB5066@redhat.com
Link: http://lkml.kernel.org/r/20170726162912.GA29716@redhat.com
Fixes:
|
|
|
Aaron Lu
|
a2468cc9bf |
swap: choose swap device according to numa node
If the system has more than one swap device and swap device has the node information, we can make use of this information to decide which swap device to use in get_swap_pages() to get better performance. The current code uses a priority based list, swap_avail_list, to decide which swap device to use and if multiple swap devices share the same priority, they are used round robin. This patch changes the previous single global swap_avail_list into a per-numa-node list, i.e. for each numa node, it sees its own priority based list of available swap devices. Swap device's priority can be promoted on its matching node's swap_avail_list. The current swap device's priority is set as: user can set a >=0 value, or the system will pick one starting from -1 then downwards. The priority value in the swap_avail_list is the negated value of the swap device's due to plist being sorted from low to high. The new policy doesn't change the semantics for priority >=0 cases, the previous starting from -1 then downwards now becomes starting from -2 then downwards and -1 is reserved as the promoted value. Take 4-node EX machine as an example, suppose 4 swap devices are available, each sit on a different node: swapA on node 0 swapB on node 1 swapC on node 2 swapD on node 3 After they are all swapped on in the sequence of ABCD. Current behaviour: their priorities will be: swapA: -1 swapB: -2 swapC: -3 swapD: -4 And their position in the global swap_avail_list will be: swapA -> swapB -> swapC -> swapD prio:1 prio:2 prio:3 prio:4 New behaviour: their priorities will be(note that -1 is skipped): swapA: -2 swapB: -3 swapC: -4 swapD: -5 And their positions in the 4 swap_avail_lists[nid] will be: swap_avail_lists[0]: /* node 0's available swap device list */ swapA -> swapB -> swapC -> swapD prio:1 prio:3 prio:4 prio:5 swap_avali_lists[1]: /* node 1's available swap device list */ swapB -> swapA -> swapC -> swapD prio:1 prio:2 prio:4 prio:5 swap_avail_lists[2]: /* node 2's available swap device list */ swapC -> swapA -> swapB -> swapD prio:1 prio:2 prio:3 prio:5 swap_avail_lists[3]: /* node 3's available swap device list */ swapD -> swapA -> swapB -> swapC prio:1 prio:2 prio:3 prio:4 To see the effect of the patch, a test that starts N process, each mmap a region of anonymous memory and then continually write to it at random position to trigger both swap in and out is used. On a 2 node Skylake EP machine with 64GiB memory, two 170GB SSD drives are used as swap devices with each attached to a different node, the result is: runtime=30m/processes=32/total test size=128G/each process mmap region=4G kernel throughput vanilla 13306 auto-binding 15169 +14% runtime=30m/processes=64/total test size=128G/each process mmap region=2G kernel throughput vanilla 11885 auto-binding 14879 +25% [aaron.lu@intel.com: v2] Link: http://lkml.kernel.org/r/20170814053130.GD2369@aaronlu.sh.intel.com Link: http://lkml.kernel.org/r/20170816024439.GA10925@aaronlu.sh.intel.com [akpm@linux-foundation.org: use kmalloc_array()] Link: http://lkml.kernel.org/r/20170814053130.GD2369@aaronlu.sh.intel.com Link: http://lkml.kernel.org/r/20170816024439.GA10925@aaronlu.sh.intel.com Signed-off-by: Aaron Lu <aaron.lu@intel.com> Cc: "Chen, Tim C" <tim.c.chen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
da99ecf117 |
mm: replace TIF_MEMDIE checks by tsk_is_oom_victim
TIF_MEMDIE is set only to the tasks whick were either directly selected by the OOM killer or passed through mark_oom_victim from the allocator path. tsk_is_oom_victim is more generic and allows to identify all tasks (threads) which share the mm with the oom victim. Please note that the freezer still needs to check TIF_MEMDIE because we cannot thaw tasks which do not participage in oom_victims counting otherwise a !TIF_MEMDIE task could interfere after oom_disbale returns. Link: http://lkml.kernel.org/r/20170810075019.28998-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
cd04ae1e2d |
mm, oom: do not rely on TIF_MEMDIE for memory reserves access
For ages we have been relying on TIF_MEMDIE thread flag to mark OOM
victims and then, among other things, to give these threads full access
to memory reserves. There are few shortcomings of this implementation,
though.
First of all and the most serious one is that the full access to memory
reserves is quite dangerous because we leave no safety room for the
system to operate and potentially do last emergency steps to move on.
Secondly this flag is per task_struct while the OOM killer operates on
mm_struct granularity so all processes sharing the given mm are killed.
Giving the full access to all these task_structs could lead to a quick
memory reserves depletion. We have tried to reduce this risk by giving
TIF_MEMDIE only to the main thread and the currently allocating task but
that doesn't really solve this problem while it surely opens up a room
for corner cases - e.g. GFP_NO{FS,IO} requests might loop inside the
allocator without access to memory reserves because a particular thread
was not the group leader.
Now that we have the oom reaper and that all oom victims are reapable
after
|
|
|
Vitaly Wool
|
d30561c56f |
z3fold: use per-cpu unbuddied lists
It's been noted that z3fold doesn't scale well when it's run in a large number of threads on many cores, which can be easily reproduced with fio 'randrw' test with --numjobs=32. E.g. the result for 1 cluster (4 cores) is: Run status group 0 (all jobs): READ: io=244785MB, aggrb=496883KB/s, minb=15527KB/s, ... WRITE: io=246735MB, aggrb=500841KB/s, minb=15651KB/s, ... While for 8 cores (2 clusters) the result is: Run status group 0 (all jobs): READ: io=244785MB, aggrb=265942KB/s, minb=8310KB/s, ... WRITE: io=246735MB, aggrb=268060KB/s, minb=8376KB/s, ... The bottleneck here is the pool lock which many threads become waiting upon. To reduce that spin lock contention, z3fold can operate only on the lists local to the current CPU whenever possible. Due to the nature of z3fold unbuddied list handling (it only takes the first entry off the list on a hot path), if the z3fold pool is big enough and balanced well enough, limiting search to only local unbuddied list doesn't lead to a significant compression ratio degrade (2.57x vs 2.65x in our measurements). This patch also introduces two worker threads: one for async in-page object layout optimization and one for releasing freed pages. This is done to speed up z3fold_free() which is often on a hot path. The fio results for 8-core case are now the following: Run status group 0 (all jobs): READ: io=244785MB, aggrb=1568.3MB/s, minb=50182KB/s, ... WRITE: io=246735MB, aggrb=1580.8MB/s, minb=50582KB/s, ... So we're in for almost 6x performance increase. Link: http://lkml.kernel.org/r/20170806181443.f9b65018f8bde25ef990f9e8@gmail.com Signed-off-by: Vitaly Wool <vitalywool@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
81a0298bdf |
mm, swap: don't use VMA based swap readahead if HDD is used as swap
VMA based swap readahead will readahead the virtual pages that is continuous in the virtual address space. While the original swap readahead will readahead the swap slots that is continuous in the swap device. Although VMA based swap readahead is more correct for the swap slots to be readahead, it will trigger more small random readings, which may cause the performance of HDD (hard disk) to degrade heavily, and may finally exceed the benefit. To avoid the issue, in this patch, if the HDD is used as swap, the VMA based swap readahead will be disabled, and the original swap readahead will be used instead. Link: http://lkml.kernel.org/r/20170807054038.1843-6-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
d9bfcfdc41 |
mm, swap: add sysfs interface for VMA based swap readahead
The sysfs interface to control the VMA based swap readahead is added as follow, /sys/kernel/mm/swap/vma_ra_enabled Enable the VMA based swap readahead algorithm, or use the original global swap readahead algorithm. /sys/kernel/mm/swap/vma_ra_max_order Set the max order of the readahead window size for the VMA based swap readahead algorithm. The corresponding ABI documentation is added too. Link: http://lkml.kernel.org/r/20170807054038.1843-5-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
ec560175c0 |
mm, swap: VMA based swap readahead
The swap readahead is an important mechanism to reduce the swap in latency. Although pure sequential memory access pattern isn't very popular for anonymous memory, the space locality is still considered valid. In the original swap readahead implementation, the consecutive blocks in swap device are readahead based on the global space locality estimation. But the consecutive blocks in swap device just reflect the order of page reclaiming, don't necessarily reflect the access pattern in virtual memory. And the different tasks in the system may have different access patterns, which makes the global space locality estimation incorrect. In this patch, when page fault occurs, the virtual pages near the fault address will be readahead instead of the swap slots near the fault swap slot in swap device. This avoid to readahead the unrelated swap slots. At the same time, the swap readahead is changed to work on per-VMA from globally. So that the different access patterns of the different VMAs could be distinguished, and the different readahead policy could be applied accordingly. The original core readahead detection and scaling algorithm is reused, because it is an effect algorithm to detect the space locality. The test and result is as follow, Common test condition ===================== Test Machine: Xeon E5 v3 (2 sockets, 72 threads, 32G RAM) Swap device: NVMe disk Micro-benchmark with combined access pattern ============================================ vm-scalability, sequential swap test case, 4 processes to eat 50G virtual memory space, repeat the sequential memory writing until 300 seconds. The first round writing will trigger swap out, the following rounds will trigger sequential swap in and out. At the same time, run vm-scalability random swap test case in background, 8 processes to eat 30G virtual memory space, repeat the random memory write until 300 seconds. This will trigger random swap-in in the background. This is a combined workload with sequential and random memory accessing at the same time. The result (for sequential workload) is as follow, Base Optimized ---- --------- throughput 345413 KB/s 414029 KB/s (+19.9%) latency.average 97.14 us 61.06 us (-37.1%) latency.50th 2 us 1 us latency.60th 2 us 1 us latency.70th 98 us 2 us latency.80th 160 us 2 us latency.90th 260 us 217 us latency.95th 346 us 369 us latency.99th 1.34 ms 1.09 ms ra_hit% 52.69% 99.98% The original swap readahead algorithm is confused by the background random access workload, so readahead hit rate is lower. The VMA-base readahead algorithm works much better. Linpack ======= The test memory size is bigger than RAM to trigger swapping. Base Optimized ---- --------- elapsed_time 393.49 s 329.88 s (-16.2%) ra_hit% 86.21% 98.82% The score of base and optimized kernel hasn't visible changes. But the elapsed time reduced and readahead hit rate improved, so the optimized kernel runs better for startup and tear down stages. And the absolute value of readahead hit rate is high, shows that the space locality is still valid in some practical workloads. Link: http://lkml.kernel.org/r/20170807054038.1843-4-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
c4fa63092f |
mm, swap: fix swap readahead marking
In the original implementation, it is possible that the existing pages in the swap cache (not newly readahead) could be marked as the readahead pages. This will cause the statistics of swap readahead be wrong and influence the swap readahead algorithm too. This is fixed via marking a page as the readahead page only if it is newly allocated and read from the disk. When testing with linpack, after the fixing the swap readahead hit rate increased from ~66% to ~86%. Link: http://lkml.kernel.org/r/20170807054038.1843-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
cbc65df240 |
mm, swap: add swap readahead hit statistics
Patch series "mm, swap: VMA based swap readahead", v4. The swap readahead is an important mechanism to reduce the swap in latency. Although pure sequential memory access pattern isn't very popular for anonymous memory, the space locality is still considered valid. In the original swap readahead implementation, the consecutive blocks in swap device are readahead based on the global space locality estimation. But the consecutive blocks in swap device just reflect the order of page reclaiming, don't necessarily reflect the access pattern in virtual memory space. And the different tasks in the system may have different access patterns, which makes the global space locality estimation incorrect. In this patchset, when page fault occurs, the virtual pages near the fault address will be readahead instead of the swap slots near the fault swap slot in swap device. This avoid to readahead the unrelated swap slots. At the same time, the swap readahead is changed to work on per-VMA from globally. So that the different access patterns of the different VMAs could be distinguished, and the different readahead policy could be applied accordingly. The original core readahead detection and scaling algorithm is reused, because it is an effect algorithm to detect the space locality. In addition to the swap readahead changes, some new sysfs interface is added to show the efficiency of the readahead algorithm and some other swap statistics. This new implementation will incur more small random read, on SSD, the improved correctness of estimation and readahead target should beat the potential increased overhead, this is also illustrated in the test results below. But on HDD, the overhead may beat the benefit, so the original implementation will be used by default. The test and result is as follow, Common test condition ===================== Test Machine: Xeon E5 v3 (2 sockets, 72 threads, 32G RAM) Swap device: NVMe disk Micro-benchmark with combined access pattern ============================================ vm-scalability, sequential swap test case, 4 processes to eat 50G virtual memory space, repeat the sequential memory writing until 300 seconds. The first round writing will trigger swap out, the following rounds will trigger sequential swap in and out. At the same time, run vm-scalability random swap test case in background, 8 processes to eat 30G virtual memory space, repeat the random memory write until 300 seconds. This will trigger random swap-in in the background. This is a combined workload with sequential and random memory accessing at the same time. The result (for sequential workload) is as follow, Base Optimized ---- --------- throughput 345413 KB/s 414029 KB/s (+19.9%) latency.average 97.14 us 61.06 us (-37.1%) latency.50th 2 us 1 us latency.60th 2 us 1 us latency.70th 98 us 2 us latency.80th 160 us 2 us latency.90th 260 us 217 us latency.95th 346 us 369 us latency.99th 1.34 ms 1.09 ms ra_hit% 52.69% 99.98% The original swap readahead algorithm is confused by the background random access workload, so readahead hit rate is lower. The VMA-base readahead algorithm works much better. Linpack ======= The test memory size is bigger than RAM to trigger swapping. Base Optimized ---- --------- elapsed_time 393.49 s 329.88 s (-16.2%) ra_hit% 86.21% 98.82% The score of base and optimized kernel hasn't visible changes. But the elapsed time reduced and readahead hit rate improved, so the optimized kernel runs better for startup and tear down stages. And the absolute value of readahead hit rate is high, shows that the space locality is still valid in some practical workloads. This patch (of 5): The statistics for total readahead pages and total readahead hits are recorded and exported via the following sysfs interface. /sys/kernel/mm/swap/ra_hits /sys/kernel/mm/swap/ra_total With them, the efficiency of the swap readahead could be measured, so that the swap readahead algorithm and parameters could be tuned accordingly. [akpm@linux-foundation.org: don't display swap stats if CONFIG_SWAP=n] Link: http://lkml.kernel.org/r/20170807054038.1843-2-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Byungchul Park
|
894e58c147 |
mm/vmalloc.c: don't reinvent the wheel but use existing llist API
Although llist provides proper APIs, they are not used. Make them used. Link: http://lkml.kernel.org/r/1502095374-16112-1-git-send-email-byungchul.park@lge.com Signed-off-by: Byungchul Park <byungchul.park@lge.com> Cc: zijun_hu <zijun_hu@htc.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joel Fernandes <joelaf@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
SeongJae Park
|
f113e64121 |
mm/vmstat.c: fix wrong comment
Comment for pagetypeinfo_showblockcount() is mistakenly duplicated from
pagetypeinfo_show_free()'s comment. This commit fixes it.
Link: http://lkml.kernel.org/r/20170809185816.11244-1-sj38.park@gmail.com
Fixes:
|
|
|
Mike Kravetz
|
749df87bd7 |
mm/shmem: add hugetlbfs support to memfd_create()
This patch came out of discussions in this e-mail thread: http://lkml.kernel.org/r/1499357846-7481-1-git-send-email-mike.kravetz%40oracle.com The Oracle JVM team is developing a new garbage collection model. This new model requires multiple mappings of the same anonymous memory. One straight forward way to accomplish this is with memfd_create. They can use the returned fd to create multiple mappings of the same memory. The JVM today has an option to use (static hugetlb) huge pages. If this option is specified, they would like to use the same garbage collection model requiring multiple mappings to the same memory. Using hugetlbfs, it is possible to explicitly mount a filesystem and specify file paths in order to get an fd that can be used for multiple mappings. However, this introduces additional system admin work and coordination. Ideally they would like to get a hugetlbfs fd without requiring explicit mounting of a filesystem. Today, mmap and shmget can make use of hugetlbfs without explicitly mounting a filesystem. The patch adds this functionality to memfd_create. Add a new flag MFD_HUGETLB to memfd_create() that will specify the file to be created resides in the hugetlbfs filesystem. This is the generic hugetlbfs filesystem not associated with any specific mount point. As with other system calls that request hugetlbfs backed pages, there is the ability to encode huge page size in the flag arguments. hugetlbfs does not support sealing operations, therefore specifying MFD_ALLOW_SEALING with MFD_HUGETLB will result in EINVAL. Of course, the memfd_man page would need updating if this type of functionality moves forward. Link: http://lkml.kernel.org/r/1502149672-7759-2-git-send-email-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Dan Williams
|
ab1b597ee0 |
mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups
devm_memremap_pages() records mapped ranges in pgmap_radix with an entry per section's worth of memory (128MB). The key for each of those entries is a section number. This leads to false positives when devm_memremap_pages() is passed a section-unaligned range as lookups in the misalignment fail to return NULL. We can close this hole by using the pfn as the key for entries in the tree. The number of entries required to describe a remapped range is reduced by leveraging multi-order entries. In practice this approach usually yields just one entry in the tree if the size and starting address are of the same power-of-2 alignment. Previously we always needed nr_entries = mapping_size / 128MB. Link: https://lists.01.org/pipermail/linux-nvdimm/2016-August/006666.html Link: http://lkml.kernel.org/r/150215410565.39310.13767886055248249438.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Toshi Kani <toshi.kani@hpe.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Wei Yang
|
c568da282b |
mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas()
In pcpu_get_vm_areas(), it checks each range is not overlapped. To make sure it is, only (N^2)/2 comparison is necessary, while current code does N^2 times. By starting from the next range, it achieves the goal and the continue could be removed. Also, - the overlap check of two ranges could be done with one clause - one typo in comment is fixed. Link: http://lkml.kernel.org/r/20170803063822.48702-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Wen Yang
|
88d6ac40c1 |
mm/vmstat: fix divide error at __fragmentation_index
When order is -1 or too big, *1UL << order* will be 0, which will cause a divide error. Although it seems that all callers of __fragmentation_index() will only do so with a valid order, the patch can make it more robust. Should prevent reoccurrences of https://bugzilla.kernel.org/show_bug.cgi?id=196555 Link: http://lkml.kernel.org/r/1501751520-2598-1-git-send-email-wen.yang99@zte.com.cn Signed-off-by: Wen Yang <wen.yang99@zte.com.cn> Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
79b63f12ab |
mm, hugetlb: do not allocate non-migrateable gigantic pages from movable zones
alloc_gigantic_page doesn't consider movability of the gigantic hugetlb
when scanning eligible ranges for the allocation. As 1GB hugetlb pages
are not movable currently this can break the movable zone assumption
that all allocations are migrateable and as such break memory hotplug.
Reorganize the code and use the standard zonelist allocations scheme
that we use for standard hugetbl pages. htlb_alloc_mask will ensure
that only migratable hugetlb pages will ever see a movable zone.
Link: http://lkml.kernel.org/r/20170803083549.21407-1-mhocko@kernel.org
Fixes:
|
|
|
Andrea Arcangeli
|
2376dd7ced |
userfaultfd: call userfaultfd_unmap_prep only if __split_vma succeeds
A __split_vma is not a worthy event to report, and it's definitely not a unmap so it would be incorrect to report unmap for the whole region to the userfaultfd manager if a __split_vma fails. So only call userfaultfd_unmap_prep after the __vma_splitting is over and do_munmap cannot fail anymore. Also add unlikely because it's better to optimize for the vast majority of apps that aren't using userfaultfd in a non cooperative way. Ideally we should also find a way to eliminate the branch entirely if CONFIG_USERFAULTFD=n, but it would complicate things so stick to unlikely for now. Link: http://lkml.kernel.org/r/20170802165145.22628-5-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Alexey Perevalov <a.perevalov@samsung.com> Cc: Maxime Coquelin <maxime.coquelin@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
c41f012ade |
mm: rename global_page_state to global_zone_page_state
global_page_state is error prone as a recent bug report pointed out [1].
It only returns proper values for zone based counters as the enum it
gets suggests. We already have global_node_page_state so let's rename
global_page_state to global_zone_page_state to be more explicit here.
All existing users seems to be correct:
$ git grep "global_page_state(NR_" | sed 's@.*(\(NR_[A-Z_]*\)).*@\1@' | sort | uniq -c
2 NR_BOUNCE
2 NR_FREE_CMA_PAGES
11 NR_FREE_PAGES
1 NR_KERNEL_STACK_KB
1 NR_MLOCK
2 NR_PAGETABLE
This patch shouldn't introduce any functional change.
[1] http://lkml.kernel.org/r/201707260628.v6Q6SmaS030814@www262.sakura.ne.jp
Link: http://lkml.kernel.org/r/20170801134256.5400-2-hannes@cmpxchg.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Mike Rapoport
|
8fb44e5403 |
userfaultfd: shmem: wire up shmem_mfill_zeropage_pte
For shmem VMAs we can use shmem_mfill_zeropage_pte for UFFDIO_ZEROPAGE Link: http://lkml.kernel.org/r/1497939652-16528-6-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Mike Rapoport
|
3217d3c79b |
userfaultfd: mcopy_atomic: introduce mfill_atomic_pte helper
Shuffle the code a bit to improve readability. Link: http://lkml.kernel.org/r/1497939652-16528-5-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Mike Rapoport
|
8d10396342 |
userfaultfd: shmem: add shmem_mfill_zeropage_pte for userfaultfd support
shmem_mfill_zeropage_pte is the low level routine that implements the userfaultfd UFFDIO_ZEROPAGE command. Since for shmem mappings zero pages are always allocated and accounted, the new method is a slight extension of the existing shmem_mcopy_atomic_pte. Link: http://lkml.kernel.org/r/1497939652-16528-4-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Mike Rapoport
|
0f07969456 |
shmem: introduce shmem_inode_acct_block
The shmem_acct_block and the update of used_blocks are following one another in all the places they are used. Combine these two into a helper function. Link: http://lkml.kernel.org/r/1497939652-16528-3-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Mike Rapoport
|
b1cc94ab2f |
shmem: shmem_charge: verify max_block is not exceeded before inode update
Patch series "userfaultfd: enable zeropage support for shmem". These patches enable support for UFFDIO_ZEROPAGE for shared memory. The first two patches are not strictly related to userfaultfd, they are just minor refactoring to reduce amount of code duplication. This patch (of 7): Currently we update inode and shmem_inode_info before verifying that used_blocks will not exceed max_blocks. In case it will, we undo the update. Let's switch the order and move the verification of the blocks count before the inode and shmem_inode_info update. Link: http://lkml.kernel.org/r/1497939652-16528-2-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
fe490cc0fe |
mm, THP, swap: add THP swapping out fallback counting
When swapping out THP (Transparent Huge Page), instead of swapping out the THP as a whole, sometimes we have to fallback to split the THP into normal pages before swapping, because no free swap clusters are available, or cgroup limit is exceeded, etc. To count the number of the fallback, a new VM event THP_SWPOUT_FALLBACK is added, and counted when we fallback to split the THP. Link: http://lkml.kernel.org/r/20170724051840.2309-13-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
bd4c82c22c |
mm, THP, swap: delay splitting THP after swapped out
In this patch, splitting transparent huge page (THP) during swapping out is delayed from after adding the THP into the swap cache to after swapping out finishes. After the patch, more operations for the anonymous THP reclaiming, such as writing the THP to the swap device, removing the THP from the swap cache could be batched. So that the performance of anonymous THP swapping out could be improved. This is the second step for the THP swap support. The plan is to delay splitting the THP step by step and avoid splitting the THP finally. With the patchset, the swap out throughput improves 42% (from about 5.81GB/s to about 8.25GB/s) in the vm-scalability swap-w-seq test case with 16 processes. At the same time, the IPI (reflect TLB flushing) reduced about 78.9%. The test is done on a Xeon E5 v3 system. The swap device used is a RAM simulated PMEM (persistent memory) device. To test the sequential swapping out, the test case creates 8 processes, which sequentially allocate and write to the anonymous pages until the RAM and part of the swap device is used up. Link: http://lkml.kernel.org/r/20170724051840.2309-12-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
d6810d7300 |
memcg, THP, swap: make mem_cgroup_swapout() support THP
This patch makes mem_cgroup_swapout() works for the transparent huge page (THP). Which will move the memory cgroup charge from memory to swap for a THP. This will be used for the THP swap support. Where a THP may be swapped out as a whole to a set of (HPAGE_PMD_NR) continuous swap slots on the swap device. Link: http://lkml.kernel.org/r/20170724051840.2309-11-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Rik van Riel <riel@redhat.com> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Shaohua Li <shli@kernel.org> Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
abe2895b76 |
memcg, THP, swap: avoid to duplicated charge THP in swap cache
For a THP (Transparent Huge Page), tail_page->mem_cgroup is NULL. So to check whether the page is charged already, we need to check the head page. This is not an issue before because it is impossible for a THP to be in the swap cache before. But after we add delaying splitting THP after swapped out support, it is possible now. Link: http://lkml.kernel.org/r/20170724051840.2309-10-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Rik van Riel <riel@redhat.com> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Shaohua Li <shli@kernel.org> Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
3e14a57b24 |
memcg, THP, swap: support move mem cgroup charge for THP swapped out
PTE mapped THP (Transparent Huge Page) will be ignored when moving memory cgroup charge. But for THP which is in the swap cache, the memory cgroup charge for the swap of a tail-page may be moved in current implementation. That isn't correct, because the swap charge for all sub-pages of a THP should be moved together. Following the processing of the PTE mapped THP, the mem cgroup charge moving for the swap entry for a tail-page of a THP is ignored too. Link: http://lkml.kernel.org/r/20170724051840.2309-9-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Rik van Riel <riel@redhat.com> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Shaohua Li <shli@kernel.org> Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
59807685a7 |
mm, THP, swap: support splitting THP for THP swap out
After adding swapping out support for THP (Transparent Huge Page), it is possible that a THP in swap cache (partly swapped out) need to be split. To split such a THP, the swap cluster backing the THP need to be split too, that is, the CLUSTER_FLAG_HUGE flag need to be cleared for the swap cluster. The patch implemented this. And because the THP swap writing needs the THP keeps as huge page during writing. The PageWriteback flag is checked before splitting. Link: http://lkml.kernel.org/r/20170724051840.2309-8-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michal Hocko <mhocko@kernel.org> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
225311a464 |
mm: test code to write THP to swap device as a whole
To support delay splitting THP (Transparent Huge Page) after swapped out, we need to enhance swap writing code to support to write a THP as a whole. This will improve swap write IO performance. As Ming Lei <ming.lei@redhat.com> pointed out, this should be based on multipage bvec support, which hasn't been merged yet. So this patch is only for testing the functionality of the other patches in the series. And will be reimplemented after multipage bvec support is merged. Link: http://lkml.kernel.org/r/20170724051840.2309-7-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Shaohua Li <shli@kernel.org> Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
f0eea189e8 |
mm, THP, swap: don't allocate huge cluster for file backed swap device
It's hard to write a whole transparent huge page (THP) to a file backed swap device during swapping out and the file backed swap device isn't very popular. So the huge cluster allocation for the file backed swap device is disabled. Link: http://lkml.kernel.org/r/20170724051840.2309-5-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michal Hocko <mhocko@kernel.org> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
ba3c4ce6de |
mm, THP, swap: make reuse_swap_page() works for THP swapped out
After supporting to delay THP (Transparent Huge Page) splitting after swapped out, it is possible that some page table mappings of the THP are turned into swap entries. So reuse_swap_page() need to check the swap count in addition to the map count as before. This patch done that. In the huge PMD write protect fault handler, in addition to the page map count, the swap count need to be checked too, so the page lock need to be acquired too when calling reuse_swap_page() in addition to the page table lock. [ying.huang@intel.com: silence a compiler warning] Link: http://lkml.kernel.org/r/87bmnzizjy.fsf@yhuang-dev.intel.com Link: http://lkml.kernel.org/r/20170724051840.2309-4-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michal Hocko <mhocko@kernel.org> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
e07098294a |
mm, THP, swap: support to reclaim swap space for THP swapped out
The normal swap slot reclaiming can be done when the swap count reaches SWAP_HAS_CACHE. But for the swap slot which is backing a THP, all swap slots backing one THP must be reclaimed together, because the swap slot may be used again when the THP is swapped out again later. So the swap slots backing one THP can be reclaimed together when the swap count for all swap slots for the THP reached SWAP_HAS_CACHE. In the patch, the functions to check whether the swap count for all swap slots backing one THP reached SWAP_HAS_CACHE are implemented and used when checking whether a swap slot can be reclaimed. To make it easier to determine whether a swap slot is backing a THP, a new swap cluster flag named CLUSTER_FLAG_HUGE is added to mark a swap cluster which is backing a THP (Transparent Huge Page). Because THP swap in as a whole isn't supported now. After deleting the THP from the swap cache (for example, swapping out finished), the CLUSTER_FLAG_HUGE flag will be cleared. So that, the normal pages inside THP can be swapped in individually. [ying.huang@intel.com: fix swap_page_trans_huge_swapped on HDD] Link: http://lkml.kernel.org/r/874ltsm0bi.fsf@yhuang-dev.intel.com Link: http://lkml.kernel.org/r/20170724051840.2309-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michal Hocko <mhocko@kernel.org> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Huang Ying
|
a3aea839e4 |
mm, THP, swap: support to clear swap cache flag for THP swapped out
Patch series "mm, THP, swap: Delay splitting THP after swapped out", v3. This is the second step of THP (Transparent Huge Page) swap optimization. In the first step, the splitting huge page is delayed from almost the first step of swapping out to after allocating the swap space for the THP and adding the THP into the swap cache. In the second step, the splitting is delayed further to after the swapping out finished. The plan is to delay splitting THP step by step, finally avoid splitting THP for the THP swapping out and swap out/in the THP as a whole. In the patchset, more operations for the anonymous THP reclaiming, such as TLB flushing, writing the THP to the swap device, removing the THP from the swap cache are batched. So that the performance of anonymous THP swapping out are improved. During the development, the following scenarios/code paths have been checked, - swap out/in - swap off - write protect page fault - madvise_free - process exit - split huge page With the patchset, the swap out throughput improves 42% (from about 5.81GB/s to about 8.25GB/s) in the vm-scalability swap-w-seq test case with 16 processes. At the same time, the IPI (reflect TLB flushing) reduced about 78.9%. The test is done on a Xeon E5 v3 system. The swap device used is a RAM simulated PMEM (persistent memory) device. To test the sequential swapping out, the test case creates 8 processes, which sequentially allocate and write to the anonymous pages until the RAM and part of the swap device is used up. Below is the part of the cover letter for the first step patchset of THP swap optimization which applies to all steps. ========================= Recently, the performance of the storage devices improved so fast that we cannot saturate the disk bandwidth with single logical CPU when do page swap out even on a high-end server machine. Because the performance of the storage device improved faster than that of single logical CPU. And it seems that the trend will not change in the near future. On the other hand, the THP becomes more and more popular because of increased memory size. So it becomes necessary to optimize THP swap performance. The advantages of the THP swap support include: - Batch the swap operations for the THP to reduce TLB flushing and lock acquiring/releasing, including allocating/freeing the swap space, adding/deleting to/from the swap cache, and writing/reading the swap space, etc. This will help improve the performance of the THP swap. - The THP swap space read/write will be 2M sequential IO. It is particularly helpful for the swap read, which are usually 4k random IO. This will improve the performance of the THP swap too. - It will help the memory fragmentation, especially when the THP is heavily used by the applications. The 2M continuous pages will be free up after THP swapping out. - It will improve the THP utilization on the system with the swap turned on. Because the speed for khugepaged to collapse the normal pages into the THP is quite slow. After the THP is split during the swapping out, it will take quite long time for the normal pages to collapse back into the THP after being swapped in. The high THP utilization helps the efficiency of the page based memory management too. There are some concerns regarding THP swap in, mainly because possible enlarged read/write IO size (for swap in/out) may put more overhead on the storage device. To deal with that, the THP swap in should be turned on only when necessary. For example, it can be selected via "always/never/madvise" logic, to be turned on globally, turned off globally, or turned on only for VMA with MADV_HUGEPAGE, etc. This patch (of 12): Previously, swapcache_free_cluster() is used only in the error path of shrink_page_list() to free the swap cluster just allocated if the THP (Transparent Huge Page) is failed to be split. In this patch, it is enhanced to clear the swap cache flag (SWAP_HAS_CACHE) for the swap cluster that holds the contents of THP swapped out. This will be used in delaying splitting THP after swapping out support. Because there is no THP swapping in as a whole support yet, after clearing the swap cache flag, the swap cluster backing the THP swapped out will be split. So that the swap slots in the swap cluster can be swapped in as normal pages later. Link: http://lkml.kernel.org/r/20170724051840.2309-2-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michal Hocko <mhocko@kernel.org> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Matthias Kaehlcke
|
04fecbf51b |
mm: memcontrol: use int for event/state parameter in several functions
Several functions use an enum type as parameter for an event/state, but are called in some locations with an argument of a different enum type. Adjust the interface of these functions to reality by changing the parameter to int. This fixes a ton of enum-conversion warnings that are generated when building the kernel with clang. [mka@chromium.org: also change parameter type of inc/dec/mod_memcg_page_state()] Link: http://lkml.kernel.org/r/20170728213442.93823-1-mka@chromium.org Link: http://lkml.kernel.org/r/20170727211004.34435-1-mka@chromium.org Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Doug Anderson <dianders@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Arvind Yadav
|
67e5ed9699 |
mm/hugetlb.c: constify attribute_group structures
attribute_group are not supposed to change at runtime. All functions working with attribute_group provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. Link: http://lkml.kernel.org/r/1501157260-3922-1-git-send-email-arvind.yadav.cs@gmail.com Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Arvind Yadav
|
8aa95a21bc |
mm/huge_memory.c: constify attribute_group structures
attribute_group are not supposed to change at runtime. All functions working with attribute_group provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. Link: http://lkml.kernel.org/r/1501157240-3876-1-git-send-email-arvind.yadav.cs@gmail.com Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Arvind Yadav
|
fd147cbb6a |
mm/page_idle.c: constify attribute_group structures
attribute_group are not supposed to change at runtime. All functions working with attribute_group provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. Link: http://lkml.kernel.org/r/1501157221-3832-1-git-send-email-arvind.yadav.cs@gmail.com Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Arvind Yadav
|
1fdaaa2329 |
mm/slub.c: constify attribute_group structures
attribute_group are not supposed to change at runtime. All functions working with attribute_group provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. Link: http://lkml.kernel.org/r/1501157186-3749-1-git-send-email-arvind.yadav.cs@gmail.com Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Arvind Yadav
|
f907c26a91 |
mm/ksm.c: constify attribute_group structures
attribute_group are not supposed to change at runtime. All functions working with attribute_group provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. Link: http://lkml.kernel.org/r/1501157167-3706-2-git-send-email-arvind.yadav.cs@gmail.com Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Roman Gushchin
|
63677c745d |
mm, memcg: reset memory.low during memcg offlining
A removed memory cgroup with a defined memory.low and some belonging
pagecache has very low chances to be freed.
If a cgroup has been removed, there is likely no memory pressure inside
the cgroup, and the pagecache is protected from the external pressure by
the defined low limit. The cgroup will be freed only after the reclaim
of all belonging pages. And it will not happen until there are any
reclaimable memory in the system. That means, there is a good chance,
that a cold pagecache will reside in the memory for an undefined amount
of time, wasting system resources.
This problem was fixed earlier by
|
|
|
Jan Kara
|
397162ffa2 |
mm: remove nr_pages argument from pagevec_lookup{,_range}()
All users of pagevec_lookup() and pagevec_lookup_range() now pass PAGEVEC_SIZE as a desired number of pages. Just drop the argument. Link: http://lkml.kernel.org/r/20170726114704.7626-11-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jan Kara
|
f7b6804687 |
mm: use find_get_pages_range() in filemap_range_has_page()
We want only pages from given range in filemap_range_has_page(), furthermore we want at most a single page. So use find_get_pages_range() instead of pagevec_lookup() and remove unnecessary code. Link: http://lkml.kernel.org/r/20170726114704.7626-10-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jan Kara
|
b947cee4b9 |
mm: implement find_get_pages_range()
Implement a variant of find_get_pages() that stops iterating at given index. This may be substantial performance gain if the mapping is sparse. See following commit for details. Furthermore lots of users of this function (through pagevec_lookup()) actually want a range lookup and all of them are currently open-coding this. Also create corresponding pagevec_lookup_range() function. Link: http://lkml.kernel.org/r/20170726114704.7626-4-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jan Kara
|
d72dc8a25a |
mm: make pagevec_lookup() update index
Make pagevec_lookup() (and underlying find_get_pages()) update index to the next page where iteration should continue. Most callers want this and also pagevec_lookup_tag() already does this. Link: http://lkml.kernel.org/r/20170726114704.7626-3-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
db73ee0d46 |
mm, vmscan: do not loop on too_many_isolated for ever
Tetsuo Handa has reported[1][2][3] that direct reclaimers might get stuck in too_many_isolated loop basically for ever because the last few pages on the LRU lists are isolated by the kswapd which is stuck on fs locks when doing the pageout or slab reclaim. This in turn means that there is nobody to actually trigger the oom killer and the system is basically unusable. too_many_isolated has been introduced by commit |
|
|
Hui Zhu
|
77ff465799 |
zsmalloc: zs_page_migrate: skip unnecessary loops but not return -EBUSY if zspage is not inuse
Getting -EBUSY from zs_page_migrate will make migration slow (retry) or fail (zs_page_putback will schedule_work free_work, but it cannot ensure the success). I noticed this issue because my Kernel patched (https://lkml.org/lkml/2014/5/28/113) that will remove retry in __alloc_contig_migrate_range. This retry will handle the -EBUSY because it will re-isolate the page and re-call migrate_pages. Without it will make cma_alloc fail at once with -EBUSY. According to the review from Minchan Kim in https://lkml.org/lkml/2014/5/28/113, I update the patch to skip unnecessary loops but not return -EBUSY if zspage is not inuse. Following is what I got with highalloc-performance in a vbox with 2 cpu 1G memory 512 zram as swap. And the swappiness is set to 100. ori ne orig new Minor Faults 50805113 50830235 Major Faults 43918 56530 Swap Ins 42087 55680 Swap Outs 89718 104700 Allocation stalls 0 0 DMA allocs 57787 52364 DMA32 allocs 47964599 48043563 Normal allocs 0 0 Movable allocs 0 0 Direct pages scanned 45493 23167 Kswapd pages scanned 1565222 1725078 Kswapd pages reclaimed 1342222 1503037 Direct pages reclaimed 45615 25186 Kswapd efficiency 85% 87% Kswapd velocity 1897.101 1949.042 Direct efficiency 100% 108% Direct velocity 55.139 26.175 Percentage direct scans 2% 1% Zone normal velocity 1952.240 1975.217 Zone dma32 velocity 0.000 0.000 Zone dma velocity 0.000 0.000 Page writes by reclaim 89764.000 105233.000 Page writes file 46 533 Page writes anon 89718 104700 Page reclaim immediate 21457 3699 Sector Reads 3259688 3441368 Sector Writes 3667252 3754836 Page rescued immediate 0 0 Slabs scanned 1042872 1160855 Direct inode steals 8042 10089 Kswapd inode steals 54295 29170 Kswapd skipped wait 0 0 THP fault alloc 175 154 THP collapse alloc 226 289 THP splits 0 0 THP fault fallback 11 14 THP collapse fail 3 2 Compaction stalls 536 646 Compaction success 322 358 Compaction failures 214 288 Page migrate success 119608 111063 Page migrate failure 2723 2593 Compaction pages isolated 250179 232652 Compaction migrate scanned 9131832 9942306 Compaction free scanned 2093272 2613998 Compaction cost 192 189 NUMA alloc hit 47124555 47193990 NUMA alloc miss 0 0 NUMA interleave hit 0 0 NUMA alloc local 47124555 47193990 NUMA base PTE updates 0 0 NUMA huge PMD updates 0 0 NUMA page range updates 0 0 NUMA hint faults 0 0 NUMA hint local faults 0 0 NUMA hint local percent 100 100 NUMA pages migrated 0 0 AutoNUMA cost 0% 0% [akpm@linux-foundation.org: remove newline, per Minchan] Link: http://lkml.kernel.org/r/1500889535-19648-1-git-send-email-zhuhui@xiaomi.com Signed-off-by: Hui Zhu <zhuhui@xiaomi.com> Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Mel Gorman
|
4647706ebe |
mm: always flush VMA ranges affected by zap_page_range
Nadav Amit report zap_page_range only specifies that the caller protect
the VMA list but does not specify whether it is held for read or write
with callers using either. madvise holds mmap_sem for read meaning that
a parallel zap operation can unmap PTEs which are then potentially
skipped by madvise which potentially returns with stale TLB entries
present. While the API could be extended, it would be a difficult API
to use. This patch causes zap_page_range() to always consider flushing
the full affected range. For small ranges or sparsely populated
mappings, this may result in one additional spurious TLB flush. For
larger ranges, it is possible that the TLB has already been flushed and
the overhead is negligible. Either way, this approach is safer overall
and avoids stale entries being present when madvise returns.
This can be illustrated with the following program provided by Nadav
Amit and slightly modified. With the patch applied, it has an exit code
of 0 indicating a stale TLB entry did not leak to userspace.
---8<---
volatile int sync_step = 0;
volatile char *p;
static inline unsigned long rdtsc()
{
unsigned long hi, lo;
__asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
return lo | (hi << 32);
}
static inline void wait_rdtsc(unsigned long cycles)
{
unsigned long tsc = rdtsc();
while (rdtsc() - tsc < cycles);
}
void *big_madvise_thread(void *ign)
{
sync_step = 1;
while (sync_step != 2);
madvise((void*)p, PAGE_SIZE * N_PAGES, MADV_DONTNEED);
}
int main(void)
{
pthread_t aux_thread;
p = mmap(0, PAGE_SIZE * N_PAGES, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
memset((void*)p, 8, PAGE_SIZE * N_PAGES);
pthread_create(&aux_thread, NULL, big_madvise_thread, NULL);
while (sync_step != 1);
*p = 8; // Cache in TLB
sync_step = 2;
wait_rdtsc(100000);
madvise((void*)p, PAGE_SIZE, MADV_DONTNEED);
printf("data: %d (%s)\n", *p, (*p == 8 ? "stale, broken" : "cleared, fine"));
return *p == 8 ? -1 : 0;
}
---8<---
Link: http://lkml.kernel.org/r/20170725101230.5v7gvnjmcnkzzql3@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Punit Agrawal
|
9b19df292c |
mm/hugetlb.c: make huge_pte_offset() consistent and document behaviour
When walking the page tables to resolve an address that points to !p*d_present() entry, huge_pte_offset() returns inconsistent values depending on the level of page table (PUD or PMD). It returns NULL in the case of a PUD entry while in the case of a PMD entry, it returns a pointer to the page table entry. A similar inconsitency exists when handling swap entries - returns NULL for a PUD entry while a pointer to the pte_t is retured for the PMD entry. Update huge_pte_offset() to make the behaviour consistent - return a pointer to the pte_t for hugepage or swap entries. Only return NULL in instances where we have a p*d_none() entry and the size parameter doesn't match the hugepage size at this level of the page table. Document the behaviour to clarify the expected behaviour of this function. This is to set clear semantics for architecture specific implementations of huge_pte_offset(). Discussions on the arm64 implementation of huge_pte_offset() (http://www.spinics.net/lists/linux-mm/msg133699.html) showed that there is benefit from returning a pte_t* in the case of p*d_none(). The fault handling code in hugetlb_fault() can handle p*d_none() entries and saves an extra round trip to huge_pte_alloc(). Other callers of huge_pte_offset() should be ok as well. [punit.agrawal@arm.com: v2] Link: http://lkml.kernel.org/r/20170725154114.24131-2-punit.agrawal@arm.com Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Oliver O'Halloran
|
09180ca4b3 |
mm/gup: make __gup_device_* require THP
These functions are the only bits of generic code that use
{pud,pmd}_pfn() without checking for CONFIG_TRANSPARENT_HUGEPAGE. This
works fine on x86, the only arch with devmap support, since the *_pfn()
functions are always defined there, but this isn't true for every
architecture.
Link: http://lkml.kernel.org/r/20170626063833.11094-1-oohall@gmail.com
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Mike Kravetz
|
dba58d3b8c |
mm/mremap: fail map duplication attempts for private mappings
mremap will attempt to create a 'duplicate' mapping if old_size == 0 is specified. In the case of private mappings, mremap will actually create a fresh separate private mapping unrelated to the original. This does not fit with the design semantics of mremap as the intention is to create a new mapping based on the original. Therefore, return EINVAL in the case where an attempt is made to duplicate a private mapping. Also, print a warning message (once) if such an attempt is made. Link: http://lkml.kernel.org/r/cb9d9f6a-7095-582f-15a5-62643d65c736@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Aaron Lu <aaron.lu@intel.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Vlastimil Babka
|
1090302794 |
mm, page_owner: don't grab zone->lock for init_pages_in_zone()
init_pages_in_zone() is run under zone->lock, which means a long lock time and disabled interrupts on large machines. This is currently not an issue since it runs early in boot, but a later patch will change that. However, like other pfn scanners, we don't actually need zone->lock even when other cpus are running. The only potentially dangerous operation here is reading bogus buddy page owner due to race, and we already know how to handle that. The worst that can happen is that we skip some early allocated pages, which should not affect the debugging power of page_owner noticeably. Link: http://lkml.kernel.org/r/20170720134029.25268-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Yang Shi <yang.shi@linaro.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: zhong jiang <zhongjiang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Vlastimil Babka
|
0fc542b7dd |
mm, page_ext: periodically reschedule during page_ext_init()
page_ext_init() can take long on large machines, so add a cond_resched() point after each section is processed. This will allow moving the init to a later point at boot without triggering lockup reports. Link: http://lkml.kernel.org/r/20170720134029.25268-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Yang Shi <yang.shi@linaro.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: zhong jiang <zhongjiang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Vlastimil Babka
|
dab4ead1a9 |
mm, page_owner: make init_pages_in_zone() faster
In init_pages_in_zone() we currently use the generic set_page_owner() function to initialize page_owner info for early allocated pages. This means we needlessly do lookup_page_ext() twice for each page, and more importantly save_stack(), which has to unwind the stack and find the corresponding stack depot handle. Because the stack is always the same for the initialization, unwind it once in init_pages_in_zone() and reuse the handle. Also avoid the repeated lookup_page_ext(). This can significantly reduce boot times with page_owner=on on large machines, especially for kernels built without frame pointer, where the stack unwinding is noticeably slower. [vbabka@suse.cz: don't duplicate code of __set_page_owner(), per Michal Hocko] [akpm@linux-foundation.org: coding-style fixes] [vbabka@suse.cz: create statically allocated fake stack trace for early allocated pages, per Michal] Link: http://lkml.kernel.org/r/45813564-2342-fc8d-d31a-f4b68a724325@suse.cz Link: http://lkml.kernel.org/r/20170720134029.25268-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Yang Shi <yang.shi@linaro.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: zhong jiang <zhongjiang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
b95046b047 |
mm, sparse, page_ext: drop ugly N_HIGH_MEMORY branches for allocations
Commit |
|
|
Michal Hocko
|
b93e0f329e |
mm, memory_hotplug: get rid of zonelists_mutex
zonelists_mutex was introduced by commit |
|
|
Michal Hocko
|
11cd8638c3 |
mm, page_alloc: remove stop_machine from build_all_zonelists
build_all_zonelists has been (ab)using stop_machine to make sure that
zonelists do not change while somebody is looking at them. This is is
just a gross hack because a) it complicates the context from which we
can call build_all_zonelists (see
|
|
|
Michal Hocko
|
9d3be21bf9 |
mm, page_alloc: simplify zonelist initialization
build_zonelists gradually builds zonelists from the nearest to the most distant node. As we do not know how many populated zones we will have in each node we rely on the _zoneref to terminate initialized part of the zonelist by a NULL zone. While this is functionally correct it is quite suboptimal because we cannot allow updaters to race with zonelists users because they could see an empty zonelist and fail the allocation or hit the OOM killer in the worst case. We can do much better, though. We can store the node ordering into an already existing node_order array and then give this array to build_zonelists_in_node_order and do the whole initialization at once. zonelists consumers still might see halfway initialized state but that should be much more tolerateable because the list will not be empty and they would either see some zone twice or skip over some zone(s) in the worst case which shouldn't lead to immediate failures. While at it let's simplify build_zonelists_node which is rather confusing now. It gets an index into the zoneref array and returns the updated index for the next iteration. Let's rename the function to build_zonerefs_node to better reflect its purpose and give it zoneref array to update. The function doesn't the index anymore. It just returns the number of added zones so that the caller can advance the zonered array start for the next update. This patch alone doesn't introduce any functional change yet, though, it is merely a preparatory work for later changes. Link: http://lkml.kernel.org/r/20170721143915.14161-7-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
34ad129657 |
mm, memory_hotplug: remove explicit build_all_zonelists from try_online_node
try_online_node calls hotadd_new_pgdat which already calls build_all_zonelists. So the additional call is redundant. Even though hotadd_new_pgdat will only initialize zonelists of the new node this is the right thing to do because such a node doesn't have any memory so other zonelists would ignore all the zones from this node anyway. Link: http://lkml.kernel.org/r/20170721143915.14161-6-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
72675e131e |
mm, memory_hotplug: drop zone from build_all_zonelists
build_all_zonelists gets a zone parameter to initialize zone's pagesets.
There is only a single user which gives a non-NULL zone parameter and
that one doesn't really need the rest of the build_all_zonelists (see
commit
|
|
|
Michal Hocko
|
d9c9a0b972 |
mm, page_alloc: do not set_cpu_numa_mem on empty nodes initialization
__build_all_zonelists reinitializes each online cpu local node for CONFIG_HAVE_MEMORYLESS_NODES. This makes sense because previously memory less nodes could gain some memory during memory hotplug and so the local node should be changed for CPUs close to such a node. It makes less sense to do that unconditionally for a newly creaded NUMA node which is still offline and without any memory. Let's also simplify the cpu loop and use for_each_online_cpu instead of an explicit cpu_online check for all possible cpus. Link: http://lkml.kernel.org/r/20170721143915.14161-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
afb6ebb3fa |
mm, page_alloc: remove boot pageset initialization from memory hotplug
boot_pageset is a boot time hack which gets superseded by normal pagesets later in the boot process. It makes zero sense to reinitialize it again and again during memory hotplug. Link: http://lkml.kernel.org/r/20170721143915.14161-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
c9bff3eebc |
mm, page_alloc: rip out ZONELIST_ORDER_ZONE
Patch series "cleanup zonelists initialization", v1. This is aimed at cleaning up the zonelists initialization code we have but the primary motivation was bug report [2] which got resolved but the usage of stop_machine is just too ugly to live. Most patches are straightforward but 3 of them need a special consideration. Patch 1 removes zone ordered zonelists completely. I am CCing linux-api because this is a user visible change. As I argue in the patch description I do not think we have a strong usecase for it these days. I have kept sysctl in place and warn into the log if somebody tries to configure zone lists ordering. If somebody has a real usecase for it we can revert this patch but I do not expect anybody will actually notice runtime differences. This patch is not strictly needed for the rest but it made patch 6 easier to implement. Patch 7 removes stop_machine from build_all_zonelists without adding any special synchronization between iterators and updater which I _believe_ is acceptable as explained in the changelog. I hope I am not missing anything. Patch 8 then removes zonelists_mutex which is kind of ugly as well and not really needed AFAICS but a care should be taken when double checking my thinking. This patch (of 9): Supporting zone ordered zonelists costs us just a lot of code while the usefulness is arguable if existent at all. Mel has already made node ordering default on 64b systems. 32b systems are still using ZONELIST_ORDER_ZONE because it is considered better to fallback to a different NUMA node rather than consume precious lowmem zones. This argument is, however, weaken by the fact that the memory reclaim has been reworked to be node rather than zone oriented. This means that lowmem requests have to skip over all highmem pages on LRUs already and so zone ordering doesn't save the reclaim time much. So the only advantage of the zone ordering is under a light memory pressure when highmem requests do not ever hit into lowmem zones and the lowmem pressure doesn't need to reclaim. Considering that 32b NUMA systems are rather suboptimal already and it is generally advisable to use 64b kernel on such a HW I believe we should rather care about the code maintainability and just get rid of ZONELIST_ORDER_ZONE altogether. Keep systcl in place and warn if somebody tries to set zone ordering either from kernel command line or the sysctl. [mhocko@suse.com: reading vm.numa_zonelist_order will never terminate] Link: http://lkml.kernel.org/r/20170721143915.14161-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Michal Hocko
|
c6f03e2903 |
mm, memory_hotplug: remove zone restrictions
Historically we have enforced that any kernel zone (e.g ZONE_NORMAL) has
to precede the Movable zone in the physical memory range. The purpose
of the movable zone is, however, not bound to any physical memory
restriction. It merely defines a class of migrateable and reclaimable
memory.
There are users (e.g. CMA) who might want to reserve specific physical
memory ranges for their own purpose. Moreover our pfn walkers have to
be prepared for zones overlapping in the physical range already because
we do support interleaving NUMA nodes and therefore zones can interleave
as well. This means we can allow each memory block to be associated
with a different zone.
Loosen the current onlining semantic and allow explicit onlining type on
any memblock. That means that online_{kernel,movable} will be allowed
regardless of the physical address of the memblock as long as it is
offline of course. This might result in moveble zone overlapping with
other kernel zones. Default onlining then becomes a bit tricky but
still sensible. echo online > memoryXY/state will online the given
block to
1) the default zone if the given range is outside of any zone
2) the enclosing zone if such a zone doesn't interleave with
any other zone
3) the default zone if more zones interleave for this range
where default zone is movable zone only if movable_node is enabled
otherwise it is a kernel zone.
Here is an example of the semantic with (movable_node is not present but
it work in an analogous way). We start with following memblocks, all of
them offline:
memory34/valid_zones:Normal Movable
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Normal Movable
memory38/valid_zones:Normal Movable
memory39/valid_zones:Normal Movable
memory40/valid_zones:Normal Movable
memory41/valid_zones:Normal Movable
Now, we online block 34 in default mode and block 37 as movable
root@test1:/sys/devices/system/node/node1# echo online > memory34/state
root@test1:/sys/devices/system/node/node1# echo online_movable > memory37/state
memory34/valid_zones:Normal
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Movable
memory38/valid_zones:Normal Movable
memory39/valid_zones:Normal Movable
memory40/valid_zones:Normal Movable
memory41/valid_zones:Normal Movable
As we can see all other blocks can still be onlined both into Normal and
Movable zones and the Normal is default because the Movable zone spans
only block37 now.
root@test1:/sys/devices/system/node/node1# echo online_movable > memory41/state
memory34/valid_zones:Normal
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Movable
memory38/valid_zones:Movable Normal
memory39/valid_zones:Movable Normal
memory40/valid_zones:Movable Normal
memory41/valid_zones:Movable
Now the default zone for blocks 37-41 has changed because movable zone
spans that range.
root@test1:/sys/devices/system/node/node1# echo online_kernel > memory39/state
memory34/valid_zones:Normal
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Movable
memory38/valid_zones:Normal Movable
memory39/valid_zones:Normal
memory40/valid_zones:Movable Normal
memory41/valid_zones:Movable
Note that the block 39 now belongs to the zone Normal and so block38
falls into Normal by default as well.
For completness
root@test1:/sys/devices/system/node/node1# for i in memory[34]?
do
echo online > $i/state 2>/dev/null
done
memory34/valid_zones:Normal
memory35/valid_zones:Normal
memory36/valid_zones:Normal
memory37/valid_zones:Movable
memory38/valid_zones:Normal
memory39/valid_zones:Normal
memory40/valid_zones:Movable
memory41/valid_zones:Movable
Implementation wise the change is quite straightforward. We can get rid
of allow_online_pfn_range altogether. online_pages allows only offline
nodes already. The original default_zone_for_pfn will become
default_kernel_zone_for_pfn. New default_zone_for_pfn implements the
above semantic. zone_for_pfn_range is slightly reorganized to implement
kernel and movable online type explicitly and MMOP_ONLINE_KEEP becomes a
catch all default behavior.
Link: http://lkml.kernel.org/r/20170714121233.16861-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kani Toshimitsu <toshi.kani@hpe.com>
Cc: <slaoub@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Michal Hocko
|
e5e6893026 |
mm, memory_hotplug: display allowed zones in the preferred ordering
Prior to commit
|
|
|
Wei Yang
|
c11525830f |
mm/memory_hotplug: just build zonelist for newly added node
Commit
|
|
|
Chris Wilson
|
d460acb5bd |
mm: track actual nr_scanned during shrink_slab()
Some shrinkers may only be able to free a bunch of objects at a time, and so free more than the requested nr_to_scan in one pass. Whilst other shrinkers may find themselves even unable to scan as many objects as they counted, and so underreport. Account for the extra freed/scanned objects against the total number of objects we intend to scan, otherwise we may end up penalising the slab far more than intended. Similarly, we want to add the underperforming scan to the deferred pass so that we try harder and harder in future passes. Link: http://lkml.kernel.org/r/20170822135325.9191-1-chris@chris-wilson.co.uk Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Shaohua Li <shli@fb.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Alexander Popov
|
ce6fa91b93 |
mm/slub.c: add a naive detection of double free or corruption
Add an assertion similar to "fasttop" check in GNU C Library allocator as a part of SLAB_FREELIST_HARDENED feature. An object added to a singly linked freelist should not point to itself. That helps to detect some double free errors (e.g. CVE-2017-2636) without slub_debug and KASAN. Link: http://lkml.kernel.org/r/1502468246-1262-1-git-send-email-alex.popov@linux.com Signed-off-by: Alexander Popov <alex.popov@linux.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Kees Cook <keescook@chromium.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Paul E McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tycho Andersen <tycho@docker.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Kees Cook
|
2482ddec67 |
mm: add SLUB free list pointer obfuscation
This SLUB free list pointer obfuscation code is modified from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. This adds a per-cache random value to SLUB caches that is XORed with their freelist pointer address and value. This adds nearly zero overhead and frustrates the very common heap overflow exploitation method of overwriting freelist pointers. A recent example of the attack is written up here: http://cyseclabs.com/blog/cve-2016-6187-heap-off-by-one-exploit and there is a section dedicated to the technique the book "A Guide to Kernel Exploitation: Attacking the Core". This is based on patches by Daniel Micay, and refactored to minimize the use of #ifdef. With 200-count cycles of "hackbench -g 20 -l 1000" I saw the following run times: before: mean 10.11882499999999999995 variance .03320378329145728642 stdev .18221905304181911048 after: mean 10.12654000000000000014 variance .04700556623115577889 stdev .21680767106160192064 The difference gets lost in the noise, but if the above is to be taken literally, using CONFIG_FREELIST_HARDENED is 0.07% slower. Link: http://lkml.kernel.org/r/20170802180609.GA66807@beast Signed-off-by: Kees Cook <keescook@chromium.org> Suggested-by: Daniel Micay <danielmicay@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Tycho Andersen <tycho@docker.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Alexander Potapenko
|
ea37df54d2 |
slub: tidy up initialization ordering
- free_kmem_cache_nodes() frees the cache node before nulling out a reference to it - init_kmem_cache_nodes() publishes the cache node before initializing it Neither of these matter at runtime because the cache nodes cannot be looked up by any other thread. But it's neater and more consistent to reorder these. Link: http://lkml.kernel.org/r/20170707083408.40410-1-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Ross Zwisler
|
d01ad197ac |
dax: remove DAX code from page_cache_tree_insert()
Now that we no longer insert struct page pointers in DAX radix trees we can remove the special casing for DAX in page_cache_tree_insert(). This also allows us to make dax_wake_mapping_entry_waiter() local to fs/dax.c, removing it from dax.h. Link: http://lkml.kernel.org/r/20170724170616.25810-5-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Ross Zwisler
|
b2770da642 |
mm: add vm_insert_mixed_mkwrite()
When servicing mmap() reads from file holes the current DAX code allocates a page cache page of all zeroes and places the struct page pointer in the mapping->page_tree radix tree. This has three major drawbacks: 1) It consumes memory unnecessarily. For every 4k page that is read via a DAX mmap() over a hole, we allocate a new page cache page. This means that if you read 1GiB worth of pages, you end up using 1GiB of zeroed memory. 2) It is slower than using a common zero page because each page fault has more work to do. Instead of just inserting a common zero page we have to allocate a page cache page, zero it, and then insert it. 3) The fact that we had to check for both DAX exceptional entries and for page cache pages in the radix tree made the DAX code more complex. This series solves these issues by following the lead of the DAX PMD code and using a common 4k zero page instead. This reduces memory usage and decreases latencies for some workloads, and it simplifies the DAX code, removing over 100 lines in total. This patch (of 5): To be able to use the common 4k zero page in DAX we need to have our PTE fault path look more like our PMD fault path where a PTE entry can be marked as dirty and writeable as it is first inserted rather than waiting for a follow-up dax_pfn_mkwrite() => finish_mkwrite_fault() call. Right now we can rely on having a dax_pfn_mkwrite() call because we can distinguish between these two cases in do_wp_page(): case 1: 4k zero page => writable DAX storage case 2: read-only DAX storage => writeable DAX storage This distinction is made by via vm_normal_page(). vm_normal_page() returns false for the common 4k zero page, though, just as it does for DAX ptes. Instead of special casing the DAX + 4k zero page case we will simplify our DAX PTE page fault sequence so that it matches our DAX PMD sequence, and get rid of the dax_pfn_mkwrite() helper. We will instead use dax_iomap_fault() to handle write-protection faults. This means that insert_pfn() needs to follow the lead of insert_pfn_pmd() and allow us to pass in a 'mkwrite' flag. If 'mkwrite' is set insert_pfn() will do the work that was previously done by wp_page_reuse() as part of the dax_pfn_mkwrite() call path. Link: http://lkml.kernel.org/r/20170724170616.25810-2-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Linus Torvalds
|
ec3604c7a5 |
Writeback error handling fixes for v4.14
-----BEGIN PGP SIGNATURE----- iQIcBAABAgAGBQJZrTy3AAoJEAAOaEEZVoIVaucP/ApBAj2S5wzvlV1u6l8E6ae7 ZeEEZfcWwzRYlKjZAkTWqj9XvGpDGO5gLq4wsZK2edFAq++/MJF8ZVtN4tdZ1kUZ DUvRodtVOrT08Kp9wZXGT7JOFrf6U/6gMcR6p0MuWnHndeKYvlpcFi9NPT4EC9/z Zm9V7gtlPdSOha7eaSjUS0+vLERkxqXLBW3Av9QUOBP/lbI3lqIroGKeHDYnVdya 2P/k5EcRRJMyJP6TqyYxmmJl+UWjJFMLvnlUDBslHnD/u3mIUhw3JLHYBjn5dZRE Xjq56IDPoXDUvzlBhtn/Uqyx+/wtwsNsylpmKv6K5G1JfdeuSsPVsCey+A1cqV64 LpE5896wf9TmnmI9LNyh6vDn925xPSGBiF45UEp5f9aO7jXeY0MaEZ8g+ENqFIDK v4gtZdS9FhYHV+/l4qEwYMKrqSbwKEs1r1FT+f4wnABby1ojfdA57ZPlp5PV2Vjp szTp88Zkb7cMvZwEnWwxWofcJNmgS7uNahvnQF3IJ4ITsioEkuyYR3K4ZQMaaaV9 wCp6G0FhXZaK3OI7o9WiDwaO2elp9Hxc8bnqKpiBbHZkY0NLh7/++5VxpeNbTHFy AGijQiiKGNNyYqNj93wq9jpVdMNjB0pXrHRxfav8v7MtQ+WfbEoAENF4T7hN7iXn UuF6eSWEC5O1UCRUk1A+ =LLY3 -----END PGP SIGNATURE----- Merge tag 'wberr-v4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux Pull writeback error handling updates from Jeff Layton: "This pile continues the work from last cycle on better tracking writeback errors. In v4.13 we added some basic errseq_t infrastructure and converted a few filesystems to use it. This set continues refining that infrastructure, adds documentation, and converts most of the other filesystems to use it. The main exception at this point is the NFS client" * tag 'wberr-v4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: ecryptfs: convert to file_write_and_wait in ->fsync mm: remove optimizations based on i_size in mapping writeback waits fs: convert a pile of fsync routines to errseq_t based reporting gfs2: convert to errseq_t based writeback error reporting for fsync fs: convert sync_file_range to use errseq_t based error-tracking mm: add file_fdatawait_range and file_write_and_wait fuse: convert to errseq_t based error tracking for fsync mm: consolidate dax / non-dax checks for writeback Documentation: add some docs for errseq_t errseq: rename __errseq_set to errseq_set |
|
|
Christoph Hellwig
|
b4bf802a5a |
mm/nommu: switch do_mmap_private to kernel_read
Instead of playing with the address limit. This also gains us validation of the kvec and proper atime updates. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
|
|
Milosz Tanski
|
3239d83484 |
fs: support IOCB_NOWAIT in generic_file_buffered_read
Allow generic_file_buffered_read to bail out early instead of waiting for the page lock or reading a page if IOCB_NOWAIT is specified. Signed-off-by: Milosz Tanski <milosz@adfin.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Sage Weil <sage@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
|
|
Christoph Hellwig
|
47c27bc469 |
fs: pass iocb to do_generic_file_read
And rename it to the more descriptive generic_file_buffered_read while at it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
|
|
Linus Torvalds
|
b1b6f83ac9 |
Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm changes from Ingo Molnar:
"PCID support, 5-level paging support, Secure Memory Encryption support
The main changes in this cycle are support for three new, complex
hardware features of x86 CPUs:
- Add 5-level paging support, which is a new hardware feature on
upcoming Intel CPUs allowing up to 128 PB of virtual address space
and 4 PB of physical RAM space - a 512-fold increase over the old
limits. (Supercomputers of the future forecasting hurricanes on an
ever warming planet can certainly make good use of more RAM.)
Many of the necessary changes went upstream in previous cycles,
v4.14 is the first kernel that can enable 5-level paging.
This feature is activated via CONFIG_X86_5LEVEL=y - disabled by
default.
(By Kirill A. Shutemov)
- Add 'encrypted memory' support, which is a new hardware feature on
upcoming AMD CPUs ('Secure Memory Encryption', SME) allowing system
RAM to be encrypted and decrypted (mostly) transparently by the
CPU, with a little help from the kernel to transition to/from
encrypted RAM. Such RAM should be more secure against various
attacks like RAM access via the memory bus and should make the
radio signature of memory bus traffic harder to intercept (and
decrypt) as well.
This feature is activated via CONFIG_AMD_MEM_ENCRYPT=y - disabled
by default.
(By Tom Lendacky)
- Enable PCID optimized TLB flushing on newer Intel CPUs: PCID is a
hardware feature that attaches an address space tag to TLB entries
and thus allows to skip TLB flushing in many cases, even if we
switch mm's.
(By Andy Lutomirski)
All three of these features were in the works for a long time, and
it's coincidence of the three independent development paths that they
are all enabled in v4.14 at once"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (65 commits)
x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)
x86/mm: Use pr_cont() in dump_pagetable()
x86/mm: Fix SME encryption stack ptr handling
kvm/x86: Avoid clearing the C-bit in rsvd_bits()
x86/CPU: Align CR3 defines
x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages
acpi, x86/mm: Remove encryption mask from ACPI page protection type
x86/mm, kexec: Fix memory corruption with SME on successive kexecs
x86/mm/pkeys: Fix typo in Documentation/x86/protection-keys.txt
x86/mm/dump_pagetables: Speed up page tables dump for CONFIG_KASAN=y
x86/mm: Implement PCID based optimization: try to preserve old TLB entries using PCID
x86: Enable 5-level paging support via CONFIG_X86_5LEVEL=y
x86/mm: Allow userspace have mappings above 47-bit
x86/mm: Prepare to expose larger address space to userspace
x86/mpx: Do not allow MPX if we have mappings above 47-bit
x86/mm: Rename tasksize_32bit/64bit to task_size_32bit/64bit()
x86/xen: Redefine XEN_ELFNOTE_INIT_P2M using PUD_SIZE * PTRS_PER_PUD
x86/mm/dump_pagetables: Fix printout of p4d level
x86/mm/dump_pagetables: Generalize address normalization
x86/boot: Fix memremap() related build failure
...
|
|
|
Ingo Molnar
|
edc2988c54 |
Merge branch 'linus' into locking/core, to fix up conflicts
Conflicts: mm/page_alloc.c Signed-off-by: Ingo Molnar <mingo@kernel.org> |
|
|
Linus Torvalds
|
1b2614f1dd |
Merge branch 'akpm' (patches from Andrew)
Merge more fixes from Andrew Morton: "6 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: scripts/dtc: fix '%zx' warning include/linux/compiler.h: don't perform compiletime_assert with -O0 mm, madvise: ensure poisoned pages are removed from per-cpu lists mm, uprobes: fix multiple free of ->uprobes_state.xol_area kernel/kthread.c: kthread_worker: don't hog the cpu mm,page_alloc: don't call __node_reclaim() with oom_lock held. |
|
|
Mel Gorman
|
c461ad6a63 |
mm, madvise: ensure poisoned pages are removed from per-cpu lists
Wendy Wang reported off-list that a RAS HWPOISON-SOFT test case failed and bisected it to the commit |
|
|
Tetsuo Handa
|
e746bf730a |
mm,page_alloc: don't call __node_reclaim() with oom_lock held.
We are doing a last second memory allocation attempt before calling out_of_memory(). But since slab shrinker functions might indirectly wait for other thread's __GFP_DIRECT_RECLAIM && !__GFP_NORETRY memory allocations via sleeping locks, calling slab shrinker functions from node_reclaim() from get_page_from_freelist() with oom_lock held has possibility of deadlock. Therefore, make sure that last second memory allocation attempt does not call slab shrinker functions. Link: http://lkml.kernel.org/r/1503577106-9196-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
5f32b26540 |
mm/mmu_notifier: kill invalidate_page
The invalidate_page callback suffered from two pitfalls. First it used
to happen after the page table lock was release and thus a new page
might have setup before the call to invalidate_page() happened.
This is in a weird way fixed by commit
|
|
|
Jérôme Glisse
|
369ea8242c |
mm/rmap: update to new mmu_notifier semantic v2
Replace all mmu_notifier_invalidate_page() calls by *_invalidate_range() and make sure it is bracketed by calls to *_invalidate_range_start()/end(). Note that because we can not presume the pmd value or pte value we have to assume the worst and unconditionaly report an invalidation as happening. Changed since v2: - try_to_unmap_one() only one call to mmu_notifier_invalidate_range() - compute end with PAGE_SIZE << compound_order(page) - fix PageHuge() case in try_to_unmap_one() Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Bernhard Held <berny156@gmx.de> Cc: Adam Borowski <kilobyte@angband.pl> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: axie <axie@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Jérôme Glisse
|
a4d1a88525 |
dax: update to new mmu_notifier semantic
Replace all mmu_notifier_invalidate_page() calls by *_invalidate_range() and make sure it is bracketed by calls to *_invalidate_range_start()/end(). Note that because we can not presume the pmd value or pte value we have to assume the worst and unconditionaly report an invalidation as happening. Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Bernhard Held <berny156@gmx.de> Cc: Adam Borowski <kilobyte@angband.pl> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: axie <axie@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Linus Torvalds
|
785373b4c3 |
Revert "rmap: do not call mmu_notifier_invalidate_page() under ptl"
This reverts commit
|
|
|
Linus Torvalds
|
9c3a815f47 |
page waitqueue: always add new entries at the end
Commit
|
|
|
Linus Torvalds
|
a8b169afbf |
Avoid page waitqueue race leaving possible page locker waiting
The "lock_page_killable()" function waits for exclusive access to the
page lock bit using the WQ_FLAG_EXCLUSIVE bit in the waitqueue entry
set.
That means that if it gets woken up, other waiters may have been
skipped.
That, in turn, means that if it sees the page being unlocked, it *must*
take that lock and return success, even if a lethal signal is also
pending.
So instead of checking for lethal signals first, we need to check for
them after we've checked the actual bit that we were waiting for. Even
if that might then delay the killing of the process.
This matches the order of the old "wait_on_bit_lock()" infrastructure
that the page locking used to use (and is still used in a few other
areas).
Note that if we still return an error after having unsuccessfully tried
to acquire the page lock, that is ok: that means that some other thread
was able to get ahead of us and lock the page, and when that other
thread then unlocks the page, the wakeup event will be repeated. So any
other pending waiters will now get properly woken up.
Fixes:
|
|
|
Linus Torvalds
|
3510ca20ec |
Minor page waitqueue cleanups
Tim Chen and Kan Liang have been battling a customer load that shows
extremely long page wakeup lists. The cause seems to be constant NUMA
migration of a hot page that is shared across a lot of threads, but the
actual root cause for the exact behavior has not been found.
Tim has a patch that batches the wait list traversal at wakeup time, so
that we at least don't get long uninterruptible cases where we traverse
and wake up thousands of processes and get nasty latency spikes. That
is likely 4.14 material, but we're still discussing the page waitqueue
specific parts of it.
In the meantime, I've tried to look at making the page wait queues less
expensive, and failing miserably. If you have thousands of threads
waiting for the same page, it will be painful. We'll need to try to
figure out the NUMA balancing issue some day, in addition to avoiding
the excessive spinlock hold times.
That said, having tried to rewrite the page wait queues, I can at least
fix up some of the braindamage in the current situation. In particular:
(a) we don't want to continue walking the page wait list if the bit
we're waiting for already got set again (which seems to be one of
the patterns of the bad load). That makes no progress and just
causes pointless cache pollution chasing the pointers.
(b) we don't want to put the non-locking waiters always on the front of
the queue, and the locking waiters always on the back. Not only is
that unfair, it means that we wake up thousands of reading threads
that will just end up being blocked by the writer later anyway.
Also add a comment about the layout of 'struct wait_page_key' - there is
an external user of it in the cachefiles code that means that it has to
match the layout of 'struct wait_bit_key' in the two first members. It
so happens to match, because 'struct page *' and 'unsigned long *' end
up having the same values simply because the page flags are the first
member in struct page.
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Christopher Lameter <cl@linux.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
Ingo Molnar
|
413d63d71b |
Merge branch 'linus' into x86/mm to pick up fixes and to fix conflicts
Conflicts: arch/x86/kernel/head64.c arch/x86/mm/mmap.c Signed-off-by: Ingo Molnar <mingo@kernel.org> |
|
|
Pavel Tatashin
|
91b540f988 |
mm/memblock.c: reversed logic in memblock_discard()
In recently introduced memblock_discard() there is a reversed logic bug.
Memory is freed of static array instead of dynamically allocated one.
Link: http://lkml.kernel.org/r/1503511441-95478-2-git-send-email-pasha.tatashin@oracle.com
Fixes:
|
|
|
Eric Biggers
|
263630e8d1 |
mm/madvise.c: fix freeing of locked page with MADV_FREE
If madvise(..., MADV_FREE) split a transparent hugepage, it called
put_page() before unlock_page().
This was wrong because put_page() can free the page, e.g. if a
concurrent madvise(..., MADV_DONTNEED) has removed it from the memory
mapping. put_page() then rightfully complained about freeing a locked
page.
Fix this by moving the unlock_page() before put_page().
This bug was found by syzkaller, which encountered the following splat:
BUG: Bad page state in process syzkaller412798 pfn:1bd800
page:ffffea0006f60000 count:0 mapcount:0 mapping: (null) index:0x20a00
flags: 0x200000000040019(locked|uptodate|dirty|swapbacked)
raw: 0200000000040019 0000000000000000 0000000000020a00 00000000ffffffff
raw: ffffea0006f60020 ffffea0006f60020 0000000000000000 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
bad because of flags: 0x1(locked)
Modules linked in:
CPU: 1 PID: 3037 Comm: syzkaller412798 Not tainted 4.13.0-rc5+ #35
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:16 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:52
bad_page+0x230/0x2b0 mm/page_alloc.c:565
free_pages_check_bad+0x1f0/0x2e0 mm/page_alloc.c:943
free_pages_check mm/page_alloc.c:952 [inline]
free_pages_prepare mm/page_alloc.c:1043 [inline]
free_pcp_prepare mm/page_alloc.c:1068 [inline]
free_hot_cold_page+0x8cf/0x12b0 mm/page_alloc.c:2584
__put_single_page mm/swap.c:79 [inline]
__put_page+0xfb/0x160 mm/swap.c:113
put_page include/linux/mm.h:814 [inline]
madvise_free_pte_range+0x137a/0x1ec0 mm/madvise.c:371
walk_pmd_range mm/pagewalk.c:50 [inline]
walk_pud_range mm/pagewalk.c:108 [inline]
walk_p4d_range mm/pagewalk.c:134 [inline]
walk_pgd_range mm/pagewalk.c:160 [inline]
__walk_page_range+0xc3a/0x1450 mm/pagewalk.c:249
walk_page_range+0x200/0x470 mm/pagewalk.c:326
madvise_free_page_range.isra.9+0x17d/0x230 mm/madvise.c:444
madvise_free_single_vma+0x353/0x580 mm/madvise.c:471
madvise_dontneed_free mm/madvise.c:555 [inline]
madvise_vma mm/madvise.c:664 [inline]
SYSC_madvise mm/madvise.c:832 [inline]
SyS_madvise+0x7d3/0x13c0 mm/madvise.c:760
entry_SYSCALL_64_fastpath+0x1f/0xbe
Here is a C reproducer:
#define _GNU_SOURCE
#include <pthread.h>
#include <sys/mman.h>
#include <unistd.h>
#define MADV_FREE 8
#define PAGE_SIZE 4096
static void *mapping;
static const size_t mapping_size = 0x1000000;
static void *madvise_thrproc(void *arg)
{
madvise(mapping, mapping_size, (long)arg);
}
int main(void)
{
pthread_t t[2];
for (;;) {
mapping = mmap(NULL, mapping_size, PROT_WRITE,
MAP_POPULATE|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
munmap(mapping + mapping_size / 2, PAGE_SIZE);
pthread_create(&t[0], 0, madvise_thrproc, (void*)MADV_DONTNEED);
pthread_create(&t[1], 0, madvise_thrproc, (void*)MADV_FREE);
pthread_join(t[0], NULL);
pthread_join(t[1], NULL);
munmap(mapping, mapping_size);
}
}
Note: to see the splat, CONFIG_TRANSPARENT_HUGEPAGE=y and
CONFIG_DEBUG_VM=y are needed.
Google Bug Id: 64696096
Link: http://lkml.kernel.org/r/20170823205235.132061-1-ebiggers3@gmail.com
Fixes:
|
|
|
Kirill A. Shutemov
|
435c0b87d6 |
mm, shmem: fix handling /sys/kernel/mm/transparent_hugepage/shmem_enabled
/sys/kernel/mm/transparent_hugepage/shmem_enabled controls if we want
to allocate huge pages when allocate pages for private in-kernel shmem
mount.
Unfortunately, as Dan noticed, I've screwed it up and the only way to
make kernel allocate huge page for the mount is to use "force" there.
All other values will be effectively ignored.
Link: http://lkml.kernel.org/r/20170822144254.66431-1-kirill.shutemov@linux.intel.com
Fixes:
|
|
|
Chen Yu
|
556b969a1c |
PM/hibernate: touch NMI watchdog when creating snapshot
There is a problem that when counting the pages for creating the hibernation snapshot will take significant amount of time, especially on system with large memory. Since the counting job is performed with irq disabled, this might lead to NMI lockup. The following warning were found on a system with 1.5TB DRAM: Freezing user space processes ... (elapsed 0.002 seconds) done. OOM killer disabled. PM: Preallocating image memory... NMI watchdog: Watchdog detected hard LOCKUP on cpu 27 CPU: 27 PID: 3128 Comm: systemd-sleep Not tainted 4.13.0-0.rc2.git0.1.fc27.x86_64 #1 task: ffff9f01971ac000 task.stack: ffffb1a3f325c000 RIP: 0010:memory_bm_find_bit+0xf4/0x100 Call Trace: swsusp_set_page_free+0x2b/0x30 mark_free_pages+0x147/0x1c0 count_data_pages+0x41/0xa0 hibernate_preallocate_memory+0x80/0x450 hibernation_snapshot+0x58/0x410 hibernate+0x17c/0x310 state_store+0xdf/0xf0 kobj_attr_store+0xf/0x20 sysfs_kf_write+0x37/0x40 kernfs_fop_write+0x11c/0x1a0 __vfs_write+0x37/0x170 vfs_write+0xb1/0x1a0 SyS_write+0x55/0xc0 entry_SYSCALL_64_fastpath+0x1a/0xa5 ... done (allocated 6590003 pages) PM: Allocated 26360012 kbytes in 19.89 seconds (1325.28 MB/s) It has taken nearly 20 seconds(2.10GHz CPU) thus the NMI lockup was triggered. In case the timeout of the NMI watch dog has been set to 1 second, a safe interval should be 6590003/20 = 320k pages in theory. However there might also be some platforms running at a lower frequency, so feed the watchdog every 100k pages. [yu.c.chen@intel.com: simplification] Link: http://lkml.kernel.org/r/1503460079-29721-1-git-send-email-yu.c.chen@intel.com [yu.c.chen@intel.com: use interval of 128k instead of 100k to avoid modulus] Link: http://lkml.kernel.org/r/1503328098-5120-1-git-send-email-yu.c.chen@intel.com Signed-off-by: Chen Yu <yu.c.chen@intel.com> Reported-by: Jan Filipcewicz <jan.filipcewicz@intel.com> Suggested-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Michal Hocko <mhocko@suse.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Len Brown <lenb@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Ingo Molnar
|
10c9850cb2 |
Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org> |
|
|
Christoph Hellwig
|
74d46992e0 |
block: replace bi_bdev with a gendisk pointer and partitions index
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> |
|
|
Linus Torvalds
|
197e7e5213 |
Sanitize 'move_pages()' permission checks
The 'move_paghes()' system call was introduced long long ago with the same permission checks as for sending a signal (except using CAP_SYS_NICE instead of CAP_SYS_KILL for the overriding capability). That turns out to not be a great choice - while the system call really only moves physical page allocations around (and you need other capabilities to do a lot of it), you can check the return value to map out some the virtual address choices and defeat ASLR of a binary that still shares your uid. So change the access checks to the more common 'ptrace_may_access()' model instead. This tightens the access checks for the uid, and also effectively changes the CAP_SYS_NICE check to CAP_SYS_PTRACE, but it's unlikely that anybody really _uses_ this legacy system call any more (we hav ebetter NUMA placement models these days), so I expect nobody to notice. Famous last words. Reported-by: Otto Ebeling <otto.ebeling@iki.fi> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
|
|
Laura Abbott
|
704b862f9e |
mm/vmalloc.c: don't unconditonally use __GFP_HIGHMEM
Commit |
|
|
zhong jiang
|
73223e4e2e |
mm/mempolicy: fix use after free when calling get_mempolicy
I hit a use after free issue when executing trinity and repoduced it
with KASAN enabled. The related call trace is as follows.
BUG: KASan: use after free in SyS_get_mempolicy+0x3c8/0x960 at addr ffff8801f582d766
Read of size 2 by task syz-executor1/798
INFO: Allocated in mpol_new.part.2+0x74/0x160 age=3 cpu=1 pid=799
__slab_alloc+0x768/0x970
kmem_cache_alloc+0x2e7/0x450
mpol_new.part.2+0x74/0x160
mpol_new+0x66/0x80
SyS_mbind+0x267/0x9f0
system_call_fastpath+0x16/0x1b
INFO: Freed in __mpol_put+0x2b/0x40 age=4 cpu=1 pid=799
__slab_free+0x495/0x8e0
kmem_cache_free+0x2f3/0x4c0
__mpol_put+0x2b/0x40
SyS_mbind+0x383/0x9f0
system_call_fastpath+0x16/0x1b
INFO: Slab 0xffffea0009cb8dc0 objects=23 used=8 fp=0xffff8801f582de40 flags=0x200000000004080
INFO: Object 0xffff8801f582d760 @offset=5984 fp=0xffff8801f582d600
Bytes b4 ffff8801f582d750: ae 01 ff ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a ........ZZZZZZZZ
Object ffff8801f582d760: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object ffff8801f582d770: 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkk.
Redzone ffff8801f582d778: bb bb bb bb bb bb bb bb ........
Padding ffff8801f582d8b8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ
Memory state around the buggy address:
ffff8801f582d600: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8801f582d680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801f582d700: fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb fc
!shared memory policy is not protected against parallel removal by other
thread which is normally protected by the mmap_sem. do_get_mempolicy,
however, drops the lock midway while we can still access it later.
Early premature up_read is a historical artifact from times when
put_user was called in this path see https://lwn.net/Articles/124754/
but that is gone since
|
|
|
Prakash Gupta
|
da094e4284 |
mm/cma_debug.c: fix stack corruption due to sprintf usage
name[] in cma_debugfs_add_one() can only accommodate 16 chars including
NULL to store sprintf output. It's common for cma device name to be
larger than 15 chars. This can cause stack corrpution. If the gcc
stack protector is turned on, this can cause a panic due to stack
corruption.
Below is one example trace:
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in:
ffffff8e69a75730
Call trace:
dump_backtrace+0x0/0x2c4
show_stack+0x20/0x28
dump_stack+0xb8/0xf4
panic+0x154/0x2b0
print_tainted+0x0/0xc0
cma_debugfs_init+0x274/0x290
do_one_initcall+0x5c/0x168
kernel_init_freeable+0x1c8/0x280
Fix the short sprintf buffer in cma_debugfs_add_one() by using
scnprintf() instead of sprintf().
Link: http://lkml.kernel.org/r/1502446217-21840-1-git-send-email-guptap@codeaurora.org
Fixes:
|
|
|
Michal Hocko
|
6b31d5955c |
mm, oom: fix potential data corruption when oom_reaper races with writer
Wenwei Tao has noticed that our current assumption that the oom victim
is dying and never doing any visible changes after it dies, and so the
oom_reaper can tear it down, is not entirely true.
__task_will_free_mem consider a task dying when SIGNAL_GROUP_EXIT is set
but do_group_exit sends SIGKILL to all threads _after_ the flag is set.
So there is a race window when some threads won't have
fatal_signal_pending while the oom_reaper could start unmapping the
address space. Moreover some paths might not check for fatal signals
before each PF/g-u-p/copy_from_user.
We already have a protection for oom_reaper vs. PF races by checking
MMF_UNSTABLE. This has been, however, checked only for kernel threads
(use_mm users) which can outlive the oom victim. A simple fix would be
to extend the current check in handle_mm_fault for all tasks but that
wouldn't be sufficient because the current check assumes that a kernel
thread would bail out after EFAULT from get_user*/copy_from_user and
never re-read the same address which would succeed because the PF path
has established page tables already. This seems to be the case for the
only existing use_mm user currently (virtio driver) but it is rather
fragile in general.
This is even more fragile in general for more complex paths such as
generic_perform_write which can re-read the same address more times
(e.g. iov_iter_copy_from_user_atomic to fail and then
iov_iter_fault_in_readable on retry).
Therefore we have to implement MMF_UNSTABLE protection in a robust way
and never make a potentially corrupted content visible. That requires
to hook deeper into the PF path and check for the flag _every time_
before a pte for anonymous memory is established (that means all
!VM_SHARED mappings).
The corruption can be triggered artificially
(http://lkml.kernel.org/r/201708040646.v746kkhC024636@www262.sakura.ne.jp)
but there doesn't seem to be any real life bug report. The race window
should be quite tight to trigger most of the time.
Link: http://lkml.kernel.org/r/20170807113839.16695-3-mhocko@kernel.org
Fixes:
|