mirror of https://gitee.com/openkylin/linux.git
12974 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Hugh Dickins
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95feeabb77 |
mm/khugepaged: fix the xas_create_range() error path
collapse_shmem()'s xas_nomem() is very unlikely to fail, but it is
rightly given a failure path, so move the whole xas_create_range() block
up before __SetPageLocked(new_page): so that it does not need to
remember to unlock_page(new_page).
Add the missing mem_cgroup_cancel_charge(), and set (currently unused)
result to SCAN_FAIL rather than SCAN_SUCCEED.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261531200.2275@eggly.anvils
Fixes:
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Hugh Dickins
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06a5e1268a |
mm/khugepaged: collapse_shmem() do not crash on Compound
collapse_shmem()'s VM_BUG_ON_PAGE(PageTransCompound) was unsafe: before
it holds page lock of the first page, racing truncation then extension
might conceivably have inserted a hugepage there already. Fail with the
SCAN_PAGE_COMPOUND result, instead of crashing (CONFIG_DEBUG_VM=y) or
otherwise mishandling the unexpected hugepage - though later we might
code up a more constructive way of handling it, with SCAN_SUCCESS.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261529310.2275@eggly.anvils
Fixes:
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Hugh Dickins
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87c460a0bd |
mm/khugepaged: collapse_shmem() without freezing new_page
khugepaged's collapse_shmem() does almost all of its work, to assemble
the huge new_page from 512 scattered old pages, with the new_page's
refcount frozen to 0 (and refcounts of all old pages so far also frozen
to 0). Including shmem_getpage() to read in any which were out on swap,
memory reclaim if necessary to allocate their intermediate pages, and
copying over all the data from old to new.
Imagine the frozen refcount as a spinlock held, but without any lock
debugging to highlight the abuse: it's not good, and under serious load
heads into lockups - speculative getters of the page are not expecting
to spin while khugepaged is rescheduled.
One can get a little further under load by hacking around elsewhere; but
fortunately, freezing the new_page turns out to have been entirely
unnecessary, with no hacks needed elsewhere.
The huge new_page lock is already held throughout, and guards all its
subpages as they are brought one by one into the page cache tree; and
anything reading the data in that page, without the lock, before it has
been marked PageUptodate, would already be in the wrong. So simply
eliminate the freezing of the new_page.
Each of the old pages remains frozen with refcount 0 after it has been
replaced by a new_page subpage in the page cache tree, until they are
all unfrozen on success or failure: just as before. They could be
unfrozen sooner, but cause no problem once no longer visible to
find_get_entry(), filemap_map_pages() and other speculative lookups.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261527570.2275@eggly.anvils
Fixes:
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Hugh Dickins
|
042a308248 |
mm/khugepaged: minor reorderings in collapse_shmem()
Several cleanups in collapse_shmem(): most of which probably do not
really matter, beyond doing things in a more familiar and reassuring
order. Simplify the failure gotos in the main loop, and on success
update stats while interrupts still disabled from the last iteration.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261526400.2275@eggly.anvils
Fixes:
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Hugh Dickins
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2af8ff2918 |
mm/khugepaged: collapse_shmem() remember to clear holes
Huge tmpfs testing reminds us that there is no __GFP_ZERO in the gfp
flags khugepaged uses to allocate a huge page - in all common cases it
would just be a waste of effort - so collapse_shmem() must remember to
clear out any holes that it instantiates.
The obvious place to do so, where they are put into the page cache tree,
is not a good choice: because interrupts are disabled there. Leave it
until further down, once success is assured, where the other pages are
copied (before setting PageUptodate).
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261525080.2275@eggly.anvils
Fixes:
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Hugh Dickins
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aaa52e3400 |
mm/khugepaged: fix crashes due to misaccounted holes
Huge tmpfs testing on a shortish file mapped into a pmd-rounded extent hit shmem_evict_inode()'s WARN_ON(inode->i_blocks) followed by clear_inode()'s BUG_ON(inode->i_data.nrpages) when the file was later closed and unlinked. khugepaged's collapse_shmem() was forgetting to update mapping->nrpages on the rollback path, after it had added but then needs to undo some holes. There is indeed an irritating asymmetry between shmem_charge(), whose callers want it to increment nrpages after successfully accounting blocks, and shmem_uncharge(), when __delete_from_page_cache() already decremented nrpages itself: oh well, just add a comment on that to them both. And shmem_recalc_inode() is supposed to be called when the accounting is expected to be in balance (so it can deduce from imbalance that reclaim discarded some pages): so change shmem_charge() to update nrpages earlier (though it's rare for the difference to matter at all). Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261523450.2275@eggly.anvils Fixes: |
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Hugh Dickins
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701270fa19 |
mm/khugepaged: collapse_shmem() stop if punched or truncated
Huge tmpfs testing showed that although collapse_shmem() recognizes a
concurrently truncated or hole-punched page correctly, its handling of
holes was liable to refill an emptied extent. Add check to stop that.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261522040.2275@eggly.anvils
Fixes:
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Hugh Dickins
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006d3ff27e |
mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()
Huge tmpfs testing, on 32-bit kernel with lockdep enabled, showed that
__split_huge_page() was using i_size_read() while holding the irq-safe
lru_lock and page tree lock, but the 32-bit i_size_read() uses an
irq-unsafe seqlock which should not be nested inside them.
Instead, read the i_size earlier in split_huge_page_to_list(), and pass
the end offset down to __split_huge_page(): all while holding head page
lock, which is enough to prevent truncation of that extent before the
page tree lock has been taken.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261520070.2275@eggly.anvils
Fixes:
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Hugh Dickins
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173d9d9fd3 |
mm/huge_memory: splitting set mapping+index before unfreeze
Huge tmpfs stress testing has occasionally hit shmem_undo_range()'s VM_BUG_ON_PAGE(page_to_pgoff(page) != index, page). Move the setting of mapping and index up before the page_ref_unfreeze() in __split_huge_page_tail() to fix this: so that a page cache lookup cannot get a reference while the tail's mapping and index are unstable. In fact, might as well move them up before the smp_wmb(): I don't see an actual need for that, but if I'm missing something, this way round is safer than the other, and no less efficient. You might argue that VM_BUG_ON_PAGE(page_to_pgoff(page) != index, page) is misplaced, and should be left until after the trylock_page(); but left as is has not crashed since, and gives more stringent assurance. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261516380.2275@eggly.anvils Fixes: |
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Hugh Dickins
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906f9cdfc2 |
mm/huge_memory: rename freeze_page() to unmap_page()
The term "freeze" is used in several ways in the kernel, and in mm it
has the particular meaning of forcing page refcount temporarily to 0.
freeze_page() is just too confusing a name for a function that unmaps a
page: rename it unmap_page(), and rename unfreeze_page() remap_page().
Went to change the mention of freeze_page() added later in mm/rmap.c,
but found it to be incorrect: ordinary page reclaim reaches there too;
but the substance of the comment still seems correct, so edit it down.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261514080.2275@eggly.anvils
Fixes:
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Andrea Arcangeli
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dcf7fe9d89 |
userfaultfd: shmem: UFFDIO_COPY: set the page dirty if VM_WRITE is not set
Set the page dirty if VM_WRITE is not set because in such case the pte
won't be marked dirty and the page would be reclaimed without writepage
(i.e. swapout in the shmem case).
This was found by source review. Most apps (certainly including QEMU)
only use UFFDIO_COPY on PROT_READ|PROT_WRITE mappings or the app can't
modify the memory in the first place. This is for correctness and it
could help the non cooperative use case to avoid unexpected data loss.
Link: http://lkml.kernel.org/r/20181126173452.26955-6-aarcange@redhat.com
Reviewed-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org
Fixes:
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Andrea Arcangeli
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e2a50c1f64 |
userfaultfd: shmem: add i_size checks
With MAP_SHARED: recheck the i_size after taking the PT lock, to
serialize against truncate with the PT lock. Delete the page from the
pagecache if the i_size_read check fails.
With MAP_PRIVATE: check the i_size after the PT lock before mapping
anonymous memory or zeropages into the MAP_PRIVATE shmem mapping.
A mostly irrelevant cleanup: like we do the delete_from_page_cache()
pagecache removal after dropping the PT lock, the PT lock is a spinlock
so drop it before the sleepable page lock.
Link: http://lkml.kernel.org/r/20181126173452.26955-5-aarcange@redhat.com
Fixes:
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Andrea Arcangeli
|
29ec90660d |
userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas
After the VMA to register the uffd onto is found, check that it has VM_MAYWRITE set before allowing registration. This way we inherit all common code checks before allowing to fill file holes in shmem and hugetlbfs with UFFDIO_COPY. The userfaultfd memory model is not applicable for readonly files unless it's a MAP_PRIVATE. Link: http://lkml.kernel.org/r/20181126173452.26955-4-aarcange@redhat.com Fixes: |
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Andrea Arcangeli
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5b51072e97 |
userfaultfd: shmem: allocate anonymous memory for MAP_PRIVATE shmem
Userfaultfd did not create private memory when UFFDIO_COPY was invoked
on a MAP_PRIVATE shmem mapping. Instead it wrote to the shmem file,
even when that had not been opened for writing. Though, fortunately,
that could only happen where there was a hole in the file.
Fix the shmem-backed implementation of UFFDIO_COPY to create private
memory for MAP_PRIVATE mappings. The hugetlbfs-backed implementation
was already correct.
This change is visible to userland, if userfaultfd has been used in
unintended ways: so it introduces a small risk of incompatibility, but
is necessary in order to respect file permissions.
An app that uses UFFDIO_COPY for anything like postcopy live migration
won't notice the difference, and in fact it'll run faster because there
will be no copy-on-write and memory waste in the tmpfs pagecache
anymore.
Userfaults on MAP_PRIVATE shmem keep triggering only on file holes like
before.
The real zeropage can also be built on a MAP_PRIVATE shmem mapping
through UFFDIO_ZEROPAGE and that's safe because the zeropage pte is
never dirty, in turn even an mprotect upgrading the vma permission from
PROT_READ to PROT_READ|PROT_WRITE won't make the zeropage pte writable.
Link: http://lkml.kernel.org/r/20181126173452.26955-3-aarcange@redhat.com
Fixes:
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Andrea Arcangeli
|
9e368259ad |
userfaultfd: use ENOENT instead of EFAULT if the atomic copy user fails
Patch series "userfaultfd shmem updates".
Jann found two bugs in the userfaultfd shmem MAP_SHARED backend: the
lack of the VM_MAYWRITE check and the lack of i_size checks.
Then looking into the above we also fixed the MAP_PRIVATE case.
Hugh by source review also found a data loss source if UFFDIO_COPY is
used on shmem MAP_SHARED PROT_READ mappings (the production usages
incidentally run with PROT_READ|PROT_WRITE, so the data loss couldn't
happen in those production usages like with QEMU).
The whole patchset is marked for stable.
We verified QEMU postcopy live migration with guest running on shmem
MAP_PRIVATE run as well as before after the fix of shmem MAP_PRIVATE.
Regardless if it's shmem or hugetlbfs or MAP_PRIVATE or MAP_SHARED, QEMU
unconditionally invokes a punch hole if the guest mapping is filebacked
and a MADV_DONTNEED too (needed to get rid of the MAP_PRIVATE COWs and
for the anon backend).
This patch (of 5):
We internally used EFAULT to communicate with the caller, switch to
ENOENT, so EFAULT can be used as a non internal retval.
Link: http://lkml.kernel.org/r/20181126173452.26955-2-aarcange@redhat.com
Fixes:
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Wei Yang
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8f416836c0 |
mm/page_alloc.c: fix calculation of pgdat->nr_zones
init_currently_empty_zone() will adjust pgdat->nr_zones and set it to
'zone_idx(zone) + 1' unconditionally. This is correct in the normal
case, while not exact in hot-plug situation.
This function is used in two places:
* free_area_init_core()
* move_pfn_range_to_zone()
In the first case, we are sure zone index increase monotonically. While
in the second one, this is under users control.
One way to reproduce this is:
----------------------------
1. create a virtual machine with empty node1
-m 4G,slots=32,maxmem=32G \
-smp 4,maxcpus=8 \
-numa node,nodeid=0,mem=4G,cpus=0-3 \
-numa node,nodeid=1,mem=0G,cpus=4-7
2. hot-add cpu 3-7
cpu-add [3-7]
2. hot-add memory to nod1
object_add memory-backend-ram,id=ram0,size=1G
device_add pc-dimm,id=dimm0,memdev=ram0,node=1
3. online memory with following order
echo online_movable > memory47/state
echo online > memory40/state
After this, node1 will have its nr_zones equals to (ZONE_NORMAL + 1)
instead of (ZONE_MOVABLE + 1).
Michal said:
"Having an incorrect nr_zones might result in all sorts of problems
which would be quite hard to debug (e.g. reclaim not considering the
movable zone). I do not expect many users would suffer from this it
but still this is trivial and obviously right thing to do so
backporting to the stable tree shouldn't be harmful (last famous
words)"
Link: http://lkml.kernel.org/r/20181117022022.9956-1-richard.weiyang@gmail.com
Fixes:
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Yu Zhao
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c1cb20d437 |
mm: use swp_offset as key in shmem_replace_page()
We changed the key of swap cache tree from swp_entry_t.val to
swp_offset. We need to do so in shmem_replace_page() as well.
Hugh said:
"shmem_replace_page() has been wrong since the day I wrote it: good
enough to work on swap "type" 0, which is all most people ever use
(especially those few who need shmem_replace_page() at all), but
broken once there are any non-0 swp_type bits set in the higher order
bits"
Link: http://lkml.kernel.org/r/20181121215442.138545-1-yuzhao@google.com
Fixes:
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Pavel Tikhomirov
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6ff38bd402 |
mm: cleancache: fix corruption on missed inode invalidation
If all pages are deleted from the mapping by memory reclaim and also
moved to the cleancache:
__delete_from_page_cache
(no shadow case)
unaccount_page_cache_page
cleancache_put_page
page_cache_delete
mapping->nrpages -= nr
(nrpages becomes 0)
We don't clean the cleancache for an inode after final file truncation
(removal).
truncate_inode_pages_final
check (nrpages || nrexceptional) is false
no truncate_inode_pages
no cleancache_invalidate_inode(mapping)
These way when reading the new file created with same inode we may get
these trash leftover pages from cleancache and see wrong data instead of
the contents of the new file.
Fix it by always doing truncate_inode_pages which is already ready for
nrpages == 0 && nrexceptional == 0 case and just invalidates inode.
[akpm@linux-foundation.org: add comment, per Jan]
Link: http://lkml.kernel.org/r/20181112095734.17979-1-ptikhomirov@virtuozzo.com
Fixes: commit
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John Hubbard
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08be37b798 |
mm/gup: finish consolidating error handling
Commit |
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Chen Chang
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45e79815b8 |
mm/memblock.c: fix a typo in __next_mem_pfn_range() comments
Link: http://lkml.kernel.org/r/20181107100247.13359-1-rainccrun@gmail.com Signed-off-by: Chen Chang <rainccrun@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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c63ae43ba5 |
mm, page_alloc: check for max order in hot path
Konstantin has noticed that kvmalloc might trigger the following warning: WARNING: CPU: 0 PID: 6676 at mm/vmstat.c:986 __fragmentation_index+0x54/0x60 [...] Call Trace: fragmentation_index+0x76/0x90 compaction_suitable+0x4f/0xf0 shrink_node+0x295/0x310 node_reclaim+0x205/0x250 get_page_from_freelist+0x649/0xad0 __alloc_pages_nodemask+0x12a/0x2a0 kmalloc_large_node+0x47/0x90 __kmalloc_node+0x22b/0x2e0 kvmalloc_node+0x3e/0x70 xt_alloc_table_info+0x3a/0x80 [x_tables] do_ip6t_set_ctl+0xcd/0x1c0 [ip6_tables] nf_setsockopt+0x44/0x60 SyS_setsockopt+0x6f/0xc0 do_syscall_64+0x67/0x120 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 the problem is that we only check for an out of bound order in the slow path and the node reclaim might happen from the fast path already. This is fixable by making sure that kvmalloc doesn't ever use kmalloc for requests that are larger than KMALLOC_MAX_SIZE but this also shows that the code is rather fragile. A recent UBSAN report just underlines that by the following report UBSAN: Undefined behaviour in mm/page_alloc.c:3117:19 shift exponent 51 is too large for 32-bit type 'int' CPU: 0 PID: 6520 Comm: syz-executor1 Not tainted 4.19.0-rc2 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xd2/0x148 lib/dump_stack.c:113 ubsan_epilogue+0x12/0x94 lib/ubsan.c:159 __ubsan_handle_shift_out_of_bounds+0x2b6/0x30b lib/ubsan.c:425 __zone_watermark_ok+0x2c7/0x400 mm/page_alloc.c:3117 zone_watermark_fast mm/page_alloc.c:3216 [inline] get_page_from_freelist+0xc49/0x44c0 mm/page_alloc.c:3300 __alloc_pages_nodemask+0x21e/0x640 mm/page_alloc.c:4370 alloc_pages_current+0xcc/0x210 mm/mempolicy.c:2093 alloc_pages include/linux/gfp.h:509 [inline] __get_free_pages+0x12/0x60 mm/page_alloc.c:4414 dma_mem_alloc+0x36/0x50 arch/x86/include/asm/floppy.h:156 raw_cmd_copyin drivers/block/floppy.c:3159 [inline] raw_cmd_ioctl drivers/block/floppy.c:3206 [inline] fd_locked_ioctl+0xa00/0x2c10 drivers/block/floppy.c:3544 fd_ioctl+0x40/0x60 drivers/block/floppy.c:3571 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0xb3c/0x1a30 block/ioctl.c:601 block_ioctl+0x105/0x150 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1c0/0x1150 fs/ioctl.c:687 ksys_ioctl+0x9e/0xb0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x7e/0xc0 fs/ioctl.c:707 do_syscall_64+0xc4/0x510 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Note that this is not a kvmalloc path. It is just that the fast path really depends on having sanitzed order as well. Therefore move the order check to the fast path. Link: http://lkml.kernel.org/r/20181113094305.GM15120@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reported-by: Kyungtae Kim <kt0755@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Byoungyoung Lee <lifeasageek@gmail.com> Cc: "Dae R. Jeong" <threeearcat@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Yufen Yu
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1a41364693 |
tmpfs: make lseek(SEEK_DATA/SEK_HOLE) return ENXIO with a negative offset
Other filesystems such as ext4, f2fs and ubifs all return ENXIO when lseek (SEEK_DATA or SEEK_HOLE) requests a negative offset. man 2 lseek says : EINVAL whence is not valid. Or: the resulting file offset would be : negative, or beyond the end of a seekable device. : : ENXIO whence is SEEK_DATA or SEEK_HOLE, and the file offset is beyond : the end of the file. Make tmpfs return ENXIO under these circumstances as well. After this, tmpfs also passes xfstests's generic/448. [akpm@linux-foundation.org: rewrite changelog] Link: http://lkml.kernel.org/r/1540434176-14349-1-git-send-email-yuyufen@huawei.com Signed-off-by: Yufen Yu <yuyufen@huawei.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Janne Huttunen
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13c9aaf7fa |
mm/vmstat.c: fix NUMA statistics updates
Scan through the whole array to see if an update is needed. While we're
at it, use sizeof() to be safe against any possible type changes in the
future.
The bug here is that we wouldn't sync per-cpu counters into global ones
if there was an update of numa_stats for higher cpus. Highly
theoretical one though because it is much more probable that zone_stats
are updated so we would refresh anyway. So I wouldn't bother to mark
this for stable, yet something nice to fix.
[mhocko@suse.com: changelog enhancement]
Link: http://lkml.kernel.org/r/1541601517-17282-1-git-send-email-janne.huttunen@nokia.com
Fixes:
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Mike Rapoport
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78179556e7 |
mm/gup.c: fix follow_page_mask() kerneldoc comment
Commit
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Michal Hocko
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9d7899999c |
mm, memory_hotplug: check zone_movable in has_unmovable_pages
Page state checks are racy. Under a heavy memory workload (e.g. stress -m 200 -t 2h) it is quite easy to hit a race window when the page is allocated but its state is not fully populated yet. A debugging patch to dump the struct page state shows has_unmovable_pages: pfn:0x10dfec00, found:0x1, count:0x0 page:ffffea0437fb0000 count:1 mapcount:1 mapping:ffff880e05239841 index:0x7f26e5000 compound_mapcount: 1 flags: 0x5fffffc0090034(uptodate|lru|active|head|swapbacked) Note that the state has been checked for both PageLRU and PageSwapBacked already. Closing this race completely would require some sort of retry logic. This can be tricky and error prone (think of potential endless or long taking loops). Workaround this problem for movable zones at least. Such a zone should only contain movable pages. Commit |
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Vasily Averin
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873d7bcfd0 |
mm/swapfile.c: use kvzalloc for swap_info_struct allocation
Commit |
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Mike Kravetz
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5e41540c8a |
hugetlbfs: fix kernel BUG at fs/hugetlbfs/inode.c:444!
This bug has been experienced several times by the Oracle DB team. The
BUG is in remove_inode_hugepages() as follows:
/*
* If page is mapped, it was faulted in after being
* unmapped in caller. Unmap (again) now after taking
* the fault mutex. The mutex will prevent faults
* until we finish removing the page.
*
* This race can only happen in the hole punch case.
* Getting here in a truncate operation is a bug.
*/
if (unlikely(page_mapped(page))) {
BUG_ON(truncate_op);
In this case, the elevated map count is not the result of a race.
Rather it was incorrectly incremented as the result of a bug in the huge
pmd sharing code. Consider the following:
- Process A maps a hugetlbfs file of sufficient size and alignment
(PUD_SIZE) that a pmd page could be shared.
- Process B maps the same hugetlbfs file with the same size and
alignment such that a pmd page is shared.
- Process B then calls mprotect() to change protections for the mapping
with the shared pmd. As a result, the pmd is 'unshared'.
- Process B then calls mprotect() again to chage protections for the
mapping back to their original value. pmd remains unshared.
- Process B then forks and process C is created. During the fork
process, we do dup_mm -> dup_mmap -> copy_page_range to copy page
tables. Copying page tables for hugetlb mappings is done in the
routine copy_hugetlb_page_range.
In copy_hugetlb_page_range(), the destination pte is obtained by:
dst_pte = huge_pte_alloc(dst, addr, sz);
If pmd sharing is possible, the returned pointer will be to a pte in an
existing page table. In the situation above, process C could share with
either process A or process B. Since process A is first in the list,
the returned pte is a pointer to a pte in process A's page table.
However, the check for pmd sharing in copy_hugetlb_page_range is:
/* If the pagetables are shared don't copy or take references */
if (dst_pte == src_pte)
continue;
Since process C is sharing with process A instead of process B, the
above test fails. The code in copy_hugetlb_page_range which follows
assumes dst_pte points to a huge_pte_none pte. It copies the pte entry
from src_pte to dst_pte and increments this map count of the associated
page. This is how we end up with an elevated map count.
To solve, check the dst_pte entry for huge_pte_none. If !none, this
implies PMD sharing so do not copy.
Link: http://lkml.kernel.org/r/20181105212315.14125-1-mike.kravetz@oracle.com
Fixes:
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Vitaly Wool
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ca0246bb97 |
z3fold: fix possible reclaim races
Reclaim and free can race on an object which is basically fine but in order for reclaim to be able to map "freed" object we need to encode object length in the handle. handle_to_chunks() is then introduced to extract object length from a handle and use it during mapping. Moreover, to avoid racing on a z3fold "headless" page release, we should not try to free that page in z3fold_free() if the reclaim bit is set. Also, in the unlikely case of trying to reclaim a page being freed, we should not proceed with that page. While at it, fix the page accounting in reclaim function. This patch supersedes "[PATCH] z3fold: fix reclaim lock-ups". Link: http://lkml.kernel.org/r/20181105162225.74e8837d03583a9b707cf559@gmail.com Signed-off-by: Vitaly Wool <vitaly.vul@sony.com> Signed-off-by: Jongseok Kim <ks77sj@gmail.com> Reported-by-by: Jongseok Kim <ks77sj@gmail.com> Reviewed-by: Snild Dolkow <snild@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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dd33ad7b25 |
memory_hotplug: cond_resched in __remove_pages
We have received a bug report that unbinding a large pmem (>1TB) can result in a soft lockup: NMI watchdog: BUG: soft lockup - CPU#9 stuck for 23s! [ndctl:4365] [...] Supported: Yes CPU: 9 PID: 4365 Comm: ndctl Not tainted 4.12.14-94.40-default #1 SLE12-SP4 Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018 task: ffff9cce7d4410c0 task.stack: ffffbe9eb1bc4000 RIP: 0010:__put_page+0x62/0x80 Call Trace: devm_memremap_pages_release+0x152/0x260 release_nodes+0x18d/0x1d0 device_release_driver_internal+0x160/0x210 unbind_store+0xb3/0xe0 kernfs_fop_write+0x102/0x180 __vfs_write+0x26/0x150 vfs_write+0xad/0x1a0 SyS_write+0x42/0x90 do_syscall_64+0x74/0x150 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x7fd13166b3d0 It has been reported on an older (4.12) kernel but the current upstream code doesn't cond_resched in the hot remove code at all and the given range to remove might be really large. Fix the issue by calling cond_resched once per memory section. Link: http://lkml.kernel.org/r/20181031125840.23982-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Thumshirn <jthumshirn@suse.de> Cc: Dan Williams <dan.j.williams@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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89c83fb539 |
mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask
THP allocation mode is quite complex and it depends on the defrag mode. This complexity is hidden in alloc_hugepage_direct_gfpmask from a large part currently. The NUMA special casing (namely __GFP_THISNODE) is however independent and placed in alloc_pages_vma currently. This both adds an unnecessary branch to all vma based page allocation requests and it makes the code more complex unnecessarily as well. Not to mention that e.g. shmem THP used to do the node reclaiming unconditionally regardless of the defrag mode until recently. This was not only unexpected behavior but it was also hardly a good default behavior and I strongly suspect it was just a side effect of the code sharing more than a deliberate decision which suggests that such a layering is wrong. Get rid of the thp special casing from alloc_pages_vma and move the logic to alloc_hugepage_direct_gfpmask. __GFP_THISNODE is applied to the resulting gfp mask only when the direct reclaim is not requested and when there is no explicit numa binding to preserve the current logic. Please note that there's also a slight difference wrt MPOL_BIND now. The previous code would avoid using __GFP_THISNODE if the local node was outside of policy_nodemask(). After this patch __GFP_THISNODE is avoided for all MPOL_BIND policies. So there's a difference that if local node is actually allowed by the bind policy's nodemask, previously __GFP_THISNODE would be added, but now it won't be. From the behavior POV this is still correct because the policy nodemask is used. Link: http://lkml.kernel.org/r/20180925120326.24392-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrea Arcangeli
|
ac5b2c1891 |
mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings
THP allocation might be really disruptive when allocated on NUMA system with the local node full or hard to reclaim. Stefan has posted an allocation stall report on 4.12 based SLES kernel which suggests the same issue: kvm: page allocation stalls for 194572ms, order:9, mode:0x4740ca(__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE|__GFP_MOVABLE|__GFP_DIRECT_RECLAIM), nodemask=(null) kvm cpuset=/ mems_allowed=0-1 CPU: 10 PID: 84752 Comm: kvm Tainted: G W 4.12.0+98-ph <a href="/view.php?id=1" title="[geschlossen] Integration Ramdisk" class="resolved">0000001</a> SLE15 (unreleased) Hardware name: Supermicro SYS-1029P-WTRT/X11DDW-NT, BIOS 2.0 12/05/2017 Call Trace: dump_stack+0x5c/0x84 warn_alloc+0xe0/0x180 __alloc_pages_slowpath+0x820/0xc90 __alloc_pages_nodemask+0x1cc/0x210 alloc_pages_vma+0x1e5/0x280 do_huge_pmd_wp_page+0x83f/0xf00 __handle_mm_fault+0x93d/0x1060 handle_mm_fault+0xc6/0x1b0 __do_page_fault+0x230/0x430 do_page_fault+0x2a/0x70 page_fault+0x7b/0x80 [...] Mem-Info: active_anon:126315487 inactive_anon:1612476 isolated_anon:5 active_file:60183 inactive_file:245285 isolated_file:0 unevictable:15657 dirty:286 writeback:1 unstable:0 slab_reclaimable:75543 slab_unreclaimable:2509111 mapped:81814 shmem:31764 pagetables:370616 bounce:0 free:32294031 free_pcp:6233 free_cma:0 Node 0 active_anon:254680388kB inactive_anon:1112760kB active_file:240648kB inactive_file:981168kB unevictable:13368kB isolated(anon):0kB isolated(file):0kB mapped:280240kB dirty:1144kB writeback:0kB shmem:95832kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 81225728kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no Node 1 active_anon:250583072kB inactive_anon:5337144kB active_file:84kB inactive_file:0kB unevictable:49260kB isolated(anon):20kB isolated(file):0kB mapped:47016kB dirty:0kB writeback:4kB shmem:31224kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 31897600kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no The defrag mode is "madvise" and from the above report it is clear that the THP has been allocated for MADV_HUGEPAGA vma. Andrea has identified that the main source of the problem is __GFP_THISNODE usage: : The problem is that direct compaction combined with the NUMA : __GFP_THISNODE logic in mempolicy.c is telling reclaim to swap very : hard the local node, instead of failing the allocation if there's no : THP available in the local node. : : Such logic was ok until __GFP_THISNODE was added to the THP allocation : path even with MPOL_DEFAULT. : : The idea behind the __GFP_THISNODE addition, is that it is better to : provide local memory in PAGE_SIZE units than to use remote NUMA THP : backed memory. That largely depends on the remote latency though, on : threadrippers for example the overhead is relatively low in my : experience. : : The combination of __GFP_THISNODE and __GFP_DIRECT_RECLAIM results in : extremely slow qemu startup with vfio, if the VM is larger than the : size of one host NUMA node. This is because it will try very hard to : unsuccessfully swapout get_user_pages pinned pages as result of the : __GFP_THISNODE being set, instead of falling back to PAGE_SIZE : allocations and instead of trying to allocate THP on other nodes (it : would be even worse without vfio type1 GUP pins of course, except it'd : be swapping heavily instead). Fix this by removing __GFP_THISNODE for THP requests which are requesting the direct reclaim. This effectivelly reverts |
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Roman Gushchin
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e68599a3c3 |
mm: handle no memcg case in memcg_kmem_charge() properly
Mike Galbraith reported a regression caused by the commit |
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Linus Torvalds
|
5f21585384 |
for-linus-20181102
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Merge tag 'for-linus-20181102' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
"The biggest part of this pull request is the revert of the blkcg
cleanup series. It had one fix earlier for a stacked device issue, but
another one was reported. Rather than play whack-a-mole with this,
revert the entire series and try again for the next kernel release.
Apart from that, only small fixes/changes.
Summary:
- Indentation fixup for mtip32xx (Colin Ian King)
- The blkcg cleanup series revert (Dennis Zhou)
- Two NVMe fixes. One fixing a regression in the nvme request
initialization in this merge window, causing nvme-fc to not work.
The other is a suspend/resume p2p resource issue (James, Keith)
- Fix sg discard merge, allowing us to merge in cases where we didn't
before (Jianchao Wang)
- Call rq_qos_exit() after the queue is frozen, preventing a hang
(Ming)
- Fix brd queue setup, fixing an oops if we fail setting up all
devices (Ming)"
* tag 'for-linus-20181102' of git://git.kernel.dk/linux-block:
nvme-pci: fix conflicting p2p resource adds
nvme-fc: fix request private initialization
blkcg: revert blkcg cleanups series
block: brd: associate with queue until adding disk
block: call rq_qos_exit() after queue is frozen
mtip32xx: clean an indentation issue, remove extraneous tabs
block: fix the DISCARD request merge
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Linus Torvalds
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c2aa1a444c |
vfs: rework data cloning infrastructure
Rework the vfs_clone_file_range and vfs_dedupe_file_range infrastructure to use a common .remap_file_range method and supply generic bounds and sanity checking functions that are shared with the data write path. The current VFS infrastructure has problems with rlimit, LFS file sizes, file time stamps, maximum filesystem file sizes, stripping setuid bits, etc and so they are addressed in these commits. We also introduce the ability for the ->remap_file_range methods to return short clones so that clones for vfs_copy_file_range() don't get rejected if the entire range can't be cloned. It also allows filesystems to sliently skip deduplication of partial EOF blocks if they are not capable of doing so without requiring errors to be thrown to userspace. All existing filesystems are converted to user the new .remap_file_range method, and both XFS and ocfs2 are modified to make use of the new generic checking infrastructure. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJb29gEAAoJEK3oKUf0dfodpOAQAL2VbHjvKXEwNMDTKscSRMmZ Z0xXo3gamFKQ+VGOqy2g2lmAYQs9SAnTuCGTJ7zIAp7u+q8gzUy5FzKAwLS4Id6L 8siaY6nzlicfO04d0MdXnWz0f3xykChgzfdQfVUlUi7WrDioBUECLPmx4a+USsp1 DQGjLOZfoOAmn2rijdnH9RTEaHqg+8mcTaLN9TRav4gGqrWxldFKXw2y6ouFC7uo /hxTRNXR9VI+EdbDelwBNXl9nU9gQA0WLOvRKwgUrtv6bSJohTPsmXt7EbBtNcVR cl3zDNc1sLD1bLaRLEUAszI/33wXaaQgom1iB51obIcHHef+JxRNG/j6rUMfzxZI VaauGv5EIvtaKN0LTAqVVLQ8t2MQFYfOr8TykmO+1UFog204aKRANdVMHDSjxD/0 dTGKJGcq+HnKQ+JHDbTdvuXEL8sUUl1FiLjOQbZPw63XmuddLKFUA2TOjXn6htbU 1h1MG5d9KjGLpabp2BQheczD08NuSmcrOBNt7IoeI3+nxr3HpMwprfB9TyaERy9X iEgyVXmjjc9bLLRW7A2wm77aW64NvPs51wKMnvuNgNwnCewrGS6cB8WVj2zbQjH1 h3f3nku44s9ctNPSBzb/sJLnpqmZQ5t0oSmrMSN+5+En6rNTacoJCzxHRJBA7z/h Z+C6y1GTZw0euY6Zjiwu =CE/A -----END PGP SIGNATURE----- Merge tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux Pull vfs dedup fixes from Dave Chinner: "This reworks the vfs data cloning infrastructure. We discovered many issues with these interfaces late in the 4.19 cycle - the worst of them (data corruption, setuid stripping) were fixed for XFS in 4.19-rc8, but a larger rework of the infrastructure fixing all the problems was needed. That rework is the contents of this pull request. Rework the vfs_clone_file_range and vfs_dedupe_file_range infrastructure to use a common .remap_file_range method and supply generic bounds and sanity checking functions that are shared with the data write path. The current VFS infrastructure has problems with rlimit, LFS file sizes, file time stamps, maximum filesystem file sizes, stripping setuid bits, etc and so they are addressed in these commits. We also introduce the ability for the ->remap_file_range methods to return short clones so that clones for vfs_copy_file_range() don't get rejected if the entire range can't be cloned. It also allows filesystems to sliently skip deduplication of partial EOF blocks if they are not capable of doing so without requiring errors to be thrown to userspace. Existing filesystems are converted to user the new remap_file_range method, and both XFS and ocfs2 are modified to make use of the new generic checking infrastructure" * tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (28 commits) xfs: remove [cm]time update from reflink calls xfs: remove xfs_reflink_remap_range xfs: remove redundant remap partial EOF block checks xfs: support returning partial reflink results xfs: clean up xfs_reflink_remap_blocks call site xfs: fix pagecache truncation prior to reflink ocfs2: remove ocfs2_reflink_remap_range ocfs2: support partial clone range and dedupe range ocfs2: fix pagecache truncation prior to reflink ocfs2: truncate page cache for clone destination file before remapping vfs: clean up generic_remap_file_range_prep return value vfs: hide file range comparison function vfs: enable remap callers that can handle short operations vfs: plumb remap flags through the vfs dedupe functions vfs: plumb remap flags through the vfs clone functions vfs: make remap_file_range functions take and return bytes completed vfs: remap helper should update destination inode metadata vfs: pass remap flags to generic_remap_checks vfs: pass remap flags to generic_remap_file_range_prep vfs: combine the clone and dedupe into a single remap_file_range ... |
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Linus Torvalds
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9931a07d51 |
Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull AFS updates from Al Viro: "AFS series, with some iov_iter bits included" * 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits) missing bits of "iov_iter: Separate type from direction and use accessor functions" afs: Probe multiple fileservers simultaneously afs: Fix callback handling afs: Eliminate the address pointer from the address list cursor afs: Allow dumping of server cursor on operation failure afs: Implement YFS support in the fs client afs: Expand data structure fields to support YFS afs: Get the target vnode in afs_rmdir() and get a callback on it afs: Calc callback expiry in op reply delivery afs: Fix FS.FetchStatus delivery from updating wrong vnode afs: Implement the YFS cache manager service afs: Remove callback details from afs_callback_break struct afs: Commit the status on a new file/dir/symlink afs: Increase to 64-bit volume ID and 96-bit vnode ID for YFS afs: Don't invoke the server to read data beyond EOF afs: Add a couple of tracepoints to log I/O errors afs: Handle EIO from delivery function afs: Fix TTL on VL server and address lists afs: Implement VL server rotation afs: Improve FS server rotation error handling ... |
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Dennis Zhou
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b5f2954d30 |
blkcg: revert blkcg cleanups series
This reverts a series committed earlier due to null pointer exception bug report in [1]. It seems there are edge case interactions that I did not consider and will need some time to understand what causes the adverse interactions. The original series can be found in [2] with a follow up series in [3]. [1] https://www.spinics.net/lists/cgroups/msg20719.html [2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/ [3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/ This reverts the following commits: |
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Linus Torvalds
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b5b1de3537 |
virtio, vhost: fixes, tweaks
virtio balloon page hinting support vhost scsi control queue misc fixes. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> -----BEGIN PGP SIGNATURE----- iQEcBAABAgAGBQJb222AAAoJECgfDbjSjVRpfHMH/1uh87pIj6Qbh9LRZm0dRVHs iEuIa0TECb+9AmqHRBliEcqWjihWnlQnSwE6d/ZTk9cH9zEEXsIu0B7nDzjGwJ5b m7wq679JqrtGpCdQhRH85sk8P3fs5ldatdbc4/0fsPwwkoXHcqTOpSZWyhtQHGc4 EkzzxHXVhVXgRBjzLXVCMoOAQ+8QfMZFrKIgKuOB0I4OVughFrAGf0Hemm18f4CL 5+YwsJQjleDkm+Udf+FTQS2oZ57DJsOLm2bwoKgqCkBaDfPlR92uWjgTa50WXggo RaokpFQkJKpz11yenezslzrVWUJApnWnUhfRd71t1ttvujrrcD9zUvWEVMURbuU= =2i/5 -----END PGP SIGNATURE----- Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost Pull virtio/vhost updates from Michael Tsirkin: "Fixes and tweaks: - virtio balloon page hinting support - vhost scsi control queue - misc fixes" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: MAINTAINERS: remove reference to bogus vsock file vhost/scsi: Use common handling code in request queue handler vhost/scsi: Extract common handling code from control queue handler vhost/scsi: Respond to control queue operations vhost/scsi: truncate T10 PI iov_iter to prot_bytes virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON mm/page_poison: expose page_poisoning_enabled to kernel modules virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT kvm_config: add CONFIG_VIRTIO_MENU |
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Linus Torvalds
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6444ccfd69 |
Merge branch 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu
Pull percpu fixes from Dennis Zhou: "Two small things for v4.20. The first fixes a clang uninitialized variable warning for arm64 in the default path calls BUILD_BUG(). The second removes an unnecessary unlikely() in a WARN_ON() use" * 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu: arm64: percpu: Initialize ret in the default case mm: percpu: remove unnecessary unlikely() |
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Fengguang Wu
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2ebe82288b |
mm/gup.c: fix __get_user_pages_fast() comment
mmu_gather_tlb() no longer exists. Replace with mmu_table_batch(). Link: http://lkml.kernel.org/r/20180928053441.rpzwafzlsnp74mkl@wfg-t540p.sh.intel.com Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Kosina <trivial@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Jan Kara
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f2c57d91b0 |
mm: Fix warning in insert_pfn()
In DAX mode a write pagefault can race with write(2) in the following
way:
CPU0 CPU1
write fault for mapped zero page (hole)
dax_iomap_rw()
iomap_apply()
xfs_file_iomap_begin()
- allocates blocks
dax_iomap_actor()
invalidate_inode_pages2_range()
- invalidates radix tree entries in given range
dax_iomap_pte_fault()
grab_mapping_entry()
- no entry found, creates empty
...
xfs_file_iomap_begin()
- finds already allocated block
...
vmf_insert_mixed_mkwrite()
- WARNs and does nothing because there
is still zero page mapped in PTE
unmap_mapping_pages()
This race results in WARN_ON from insert_pfn() and is occasionally
triggered by fstest generic/344. Note that the race is otherwise
harmless as before write(2) on CPU0 is finished, we will invalidate page
tables properly and thus user of mmap will see modified data from
write(2) from that point on. So just restrict the warning only to the
case when the PFN in PTE is not zero page.
Link: http://lkml.kernel.org/r/20180824154542.26872-1-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Hildenbrand
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381eab4a6e |
mm/memory_hotplug: fix online/offline_pages called w.o. mem_hotplug_lock
There seem to be some problems as result of |
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David Hildenbrand
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8df1d0e4a2 |
mm/memory_hotplug: make add_memory() take the device_hotplug_lock
add_memory() currently does not take the device_hotplug_lock, however
is aleady called under the lock from
arch/powerpc/platforms/pseries/hotplug-memory.c
drivers/acpi/acpi_memhotplug.c
to synchronize against CPU hot-remove and similar.
In general, we should hold the device_hotplug_lock when adding memory to
synchronize against online/offline request (e.g. from user space) - which
already resulted in lock inversions due to device_lock() and
mem_hotplug_lock - see
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David Hildenbrand
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d15e59260f |
mm/memory_hotplug: make remove_memory() take the device_hotplug_lock
Patch series "mm: online/offline_pages called w.o. mem_hotplug_lock", v3. Reading through the code and studying how mem_hotplug_lock is to be used, I noticed that there are two places where we can end up calling device_online()/device_offline() - online_pages()/offline_pages() without the mem_hotplug_lock. And there are other places where we call device_online()/device_offline() without the device_hotplug_lock. While e.g. echo "online" > /sys/devices/system/memory/memory9/state is fine, e.g. echo 1 > /sys/devices/system/memory/memory9/online Will not take the mem_hotplug_lock. However the device_lock() and device_hotplug_lock. E.g. via memory_probe_store(), we can end up calling add_memory()->online_pages() without the device_hotplug_lock. So we can have concurrent callers in online_pages(). We e.g. touch in online_pages() basically unprotected zone->present_pages then. Looks like there is a longer history to that (see Patch #2 for details), and fixing it to work the way it was intended is not really possible. We would e.g. have to take the mem_hotplug_lock in device/base/core.c, which sounds wrong. Summary: We had a lock inversion on mem_hotplug_lock and device_lock(). More details can be found in patch 3 and patch 6. I propose the general rules (documentation added in patch 6): 1. add_memory/add_memory_resource() must only be called with device_hotplug_lock. 2. remove_memory() must only be called with device_hotplug_lock. This is already documented and holds for all callers. 3. device_online()/device_offline() must only be called with device_hotplug_lock. This is already documented and true for now in core code. Other callers (related to memory hotplug) have to be fixed up. 4. mem_hotplug_lock is taken inside of add_memory/remove_memory/ online_pages/offline_pages. To me, this looks way cleaner than what we have right now (and easier to verify). And looking at the documentation of remove_memory, using lock_device_hotplug also for add_memory() feels natural. This patch (of 6): remove_memory() is exported right now but requires the device_hotplug_lock, which is not exported. So let's provide a variant that takes the lock and only export that one. The lock is already held in arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c arch/powerpc/platforms/powernv/memtrace.c Apart from that, there are not other users in the tree. Link: http://lkml.kernel.org/r/20180925091457.28651-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Rashmica Gupta <rashmica.g@gmail.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mike Rapoport
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2f770806fd |
mm/memblock.c: warn if zero alignment was requested
After updating all memblock users to explicitly specify SMP_CACHE_BYTES alignment rather than use 0, it is still possible that uncovered users may sneak in. Add a WARN_ON_ONCE for such cases. [sfr@canb.auug.org.au: use dump_stack() instead of WARN_ON_ONCE for the alignment checks] Link: http://lkml.kernel.org/r/20181016131927.6ceba6ab@canb.auug.org.au [akpm@linux-foundation.org: add apologetic comment] Link: http://lkml.kernel.org/r/20181011060850.GA19822@rapoport-lnx Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mike Rapoport
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7e1c4e2792 |
memblock: stop using implicit alignment to SMP_CACHE_BYTES
When a memblock allocation APIs are called with align = 0, the alignment is implicitly set to SMP_CACHE_BYTES. Implicit alignment is done deep in the memblock allocator and it can come as a surprise. Not that such an alignment would be wrong even when used incorrectly but it is better to be explicit for the sake of clarity and the prinicple of the least surprise. Replace all such uses of memblock APIs with the 'align' parameter explicitly set to SMP_CACHE_BYTES and stop implicit alignment assignment in the memblock internal allocation functions. For the case when memblock APIs are used via helper functions, e.g. like iommu_arena_new_node() in Alpha, the helper functions were detected with Coccinelle's help and then manually examined and updated where appropriate. The direct memblock APIs users were updated using the semantic patch below: @@ expression size, min_addr, max_addr, nid; @@ ( | - memblock_alloc_try_nid_raw(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid_raw(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc_try_nid_nopanic(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid_nopanic(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc_try_nid(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc(size, 0) + memblock_alloc(size, SMP_CACHE_BYTES) | - memblock_alloc_raw(size, 0) + memblock_alloc_raw(size, SMP_CACHE_BYTES) | - memblock_alloc_from(size, 0, min_addr) + memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr) | - memblock_alloc_nopanic(size, 0) + memblock_alloc_nopanic(size, SMP_CACHE_BYTES) | - memblock_alloc_low(size, 0) + memblock_alloc_low(size, SMP_CACHE_BYTES) | - memblock_alloc_low_nopanic(size, 0) + memblock_alloc_low_nopanic(size, SMP_CACHE_BYTES) | - memblock_alloc_from_nopanic(size, 0, min_addr) + memblock_alloc_from_nopanic(size, SMP_CACHE_BYTES, min_addr) | - memblock_alloc_node(size, 0, nid) + memblock_alloc_node(size, SMP_CACHE_BYTES, nid) ) [mhocko@suse.com: changelog update] [akpm@linux-foundation.org: coding-style fixes] [rppt@linux.ibm.com: fix missed uses of implicit alignment] Link: http://lkml.kernel.org/r/20181016133656.GA10925@rapoport-lnx Link: http://lkml.kernel.org/r/1538687224-17535-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Paul Burton <paul.burton@mips.com> [MIPS] Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mike Rapoport
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57c8a661d9 |
mm: remove include/linux/bootmem.h
Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include <linux/memblock.h> @@ @@ - #include <linux/bootmem.h> + #include <linux/memblock.h> [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mike Rapoport
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97ad1087ef |
memblock: replace BOOTMEM_ALLOC_* with MEMBLOCK variants
Drop BOOTMEM_ALLOC_ACCESSIBLE and BOOTMEM_ALLOC_ANYWHERE in favor of identical MEMBLOCK definitions. Link: http://lkml.kernel.org/r/1536927045-23536-29-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mike Rapoport
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bda49a8116 |
mm: remove nobootmem
Move a few remaining functions from nobootmem.c to memblock.c and remove nobootmem Link: http://lkml.kernel.org/r/1536927045-23536-28-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mike Rapoport
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7c2ee349cf |
memblock: rename __free_pages_bootmem to memblock_free_pages
The conversion is done using
sed -i 's@__free_pages_bootmem@memblock_free_pages@' \
$(git grep -l __free_pages_bootmem)
Link: http://lkml.kernel.org/r/1536927045-23536-27-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mike Rapoport
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c6ffc5ca8f |
memblock: rename free_all_bootmem to memblock_free_all
The conversion is done using
sed -i 's@free_all_bootmem@memblock_free_all@' \
$(git grep -l free_all_bootmem)
Link: http://lkml.kernel.org/r/1536927045-23536-26-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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