As pointed out by Linus, commit dab5855 ("perf_counter: Add mmap event hooks to
mprotect()") is fundamentally wrong as mprotect_fixup() can free 'vma' due to
merging. Fix the problem by moving perf_event_mmap() hook to
mprotect_fixup().
Note: there's another successful return path from mprotect_fixup() if old
flags equal to new flags. We don't, however, need to call
perf_event_mmap() there because 'perf' already knows the VMA is
executable.
Reported-by: Dave Jones <davej@redhat.com>
Analyzed-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are two places, that do not release the slub_lock.
Respective bugs were introduced by sysfs changes ab4d5ed5 (slub: Enable
sysfs support for !CONFIG_SLUB_DEBUG) and 2bce6485 ( slub: Allow removal
of slab caches during boot).
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Having the trace calls defined in the always inlined kmalloc functions
in include/linux/slub_def.h causes a lot of code duplication as the
trace functions get instantiated for each kamalloc call site. This can
simply be removed by pushing the trace calls down into the functions in
slub.c.
On my x86_64 built this patch shrinks the code size of the kernel by
approx 36K and also shrinks the code size of many modules -- too many to
list here ;)
size vmlinux (2.6.36) reports
text data bss dec hex filename
5410611 743172 828928 6982711 6a8c37 vmlinux
5373738 744244 828928 6946910 6a005e vmlinux + patch
The resulting kernel has had some testing & kmalloc trace still seems to
work.
This patch
- moves trace_kmalloc out of the inlined kmalloc() and pushes it down
into kmem_cache_alloc_trace() so this it only get instantiated once.
- rename kmem_cache_alloc_notrace() to kmem_cache_alloc_trace() to
indicate that now is does have tracing. (maybe this would better being
called something like kmalloc_kmem_cache ?)
- adds a new function kmalloc_order() to handle allocation and tracing
of large allocations of page order.
- removes tracing from the inlined kmalloc_large() replacing them with a
call to kmalloc_order();
- move tracing out of inlined kmalloc_node() and pushing it down into
kmem_cache_alloc_node_trace
- rename kmem_cache_alloc_node_notrace() to
kmem_cache_alloc_node_trace()
- removes the include of trace/events/kmem.h from slub_def.h.
v2
- keep kmalloc_order_trace inline when !CONFIG_TRACE
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This slipped by when unifying the filemap and swap versions of
lock_page_or_retry()...
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Normal syscall audit doesn't catch 5th argument of syscall. It also
doesn't catch the contents of userland structures pointed to be
syscall argument, so for both old and new mmap(2) ABI it doesn't
record the descriptor we are mapping. For old one it also misses
flags.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When a node contains only HighMem memory, slab_node(MPOL_BIND)
dereferences a NULL pointer.
[ This code seems to go back all the way to commit 19770b32609b: "mm:
filter based on a nodemask as well as a gfp_mask". Which was back in
April 2008, and it got merged into 2.6.26. - Linus ]
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300: (44 commits)
MN10300: Save frame pointer in thread_info struct rather than global var
MN10300: Change "Matsushita" to "Panasonic".
MN10300: Create a defconfig for the ASB2364 board
MN10300: Update the ASB2303 defconfig
MN10300: ASB2364: Add support for SMSC911X and SMC911X
MN10300: ASB2364: Handle the IRQ multiplexer in the FPGA
MN10300: Generic time support
MN10300: Specify an ELF HWCAP flag for MN10300 Atomic Operations Unit support
MN10300: Map userspace atomic op regs as a vmalloc page
MN10300: And Panasonic AM34 subarch and implement SMP
MN10300: Delete idle_timestamp from irq_cpustat_t
MN10300: Make various interrupt priority settings configurable
MN10300: Optimise do_csum()
MN10300: Implement atomic ops using atomic ops unit
MN10300: Make the FPU operate in non-lazy mode under SMP
MN10300: SMP TLB flushing
MN10300: Use the [ID]PTEL2 registers rather than [ID]PTEL for TLB control
MN10300: Make the use of PIDR to mark TLB entries controllable
MN10300: Rename __flush_tlb*() to local_flush_tlb*()
MN10300: AM34 erratum requires MMUCTR read and write on exception entry
...
Replace iterated page_cache_release() with release_pages(), which is
faster and shorter.
Needs release_pages() to be exported to modules.
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch extracts the core logic from mem_cgroup_update_file_mapped() as
mem_cgroup_update_file_stat() and adds a wrapper.
As a planned future update, memory cgroup has to count dirty pages to
implement dirty_ratio/limit. And more, the number of dirty pages is
required to kick flusher thread to start writeback. (Now, no kick.)
This patch is preparation for it and makes other statistics implementation
clearer. Just a clean up.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Reviewed-by: Greg Thelen <gthelen@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
An event counter MEM_CGROUP_ON_MOVE is used for quick check whether file
stat update can be done in async manner or not. Now, it use percpu
counter and for_each_possible_cpu to update.
This patch replaces for_each_possible_cpu to for_each_online_cpu and adds
necessary synchronization logic at CPU HOTPLUG.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, memcgroup's per cpu coutner uses for_each_possible_cpu() to get the
value. It's better to use for_each_online_cpu() and a cpu hotplug
handler.
This patch only handles statistics counter. MEM_CGROUP_ON_MOVE will be
handled in another patch.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In memory cgroup management, we sometimes have to walk through
subhierarchy of cgroup to gather informaiton, or lock something, etc.
Now, to do that, mem_cgroup_walk_tree() function is provided. It calls
given callback function per cgroup found. But the bad thing is that it
has to pass a fixed style function and argument, "void*" and it adds much
type casting to memcontrol.c.
To make the code clean, this patch replaces walk_tree() with
for_each_mem_cgroup_tree(iter, root)
An iterator style call. The good point is that iterator call doesn't have
to assume what kind of function is called under it. A bad point is that
it may cause reference-count leak if a caller use "break" from the loop by
mistake.
I think the benefit is larger. The modified code seems straigtforward and
easy to read because we don't have misterious callbacks and pointer cast.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At accounting file events per memory cgroup, we need to find memory cgroup
via page_cgroup->mem_cgroup. Now, we use lock_page_cgroup() for guarantee
pc->mem_cgroup is not overwritten while we make use of it.
But, considering the context which page-cgroup for files are accessed,
we can use alternative light-weight mutual execusion in the most case.
At handling file-caches, the only race we have to take care of is "moving"
account, IOW, overwriting page_cgroup->mem_cgroup. (See comment in the
patch)
Unlike charge/uncharge, "move" happens not so frequently. It happens only when
rmdir() and task-moving (with a special settings.)
This patch adds a race-checker for file-cache-status accounting v.s. account
moving. The new per-cpu-per-memcg counter MEM_CGROUP_ON_MOVE is added.
The routine for account move
1. Increment it before start moving
2. Call synchronize_rcu()
3. Decrement it after the end of moving.
By this, file-status-counting routine can check it needs to call
lock_page_cgroup(). In most case, I doesn't need to call it.
Following is a perf data of a process which mmap()/munmap 32MB of file cache
in a minute.
Before patch:
28.25% mmap mmap [.] main
22.64% mmap [kernel.kallsyms] [k] page_fault
9.96% mmap [kernel.kallsyms] [k] mem_cgroup_update_file_mapped
3.67% mmap [kernel.kallsyms] [k] filemap_fault
3.50% mmap [kernel.kallsyms] [k] unmap_vmas
2.99% mmap [kernel.kallsyms] [k] __do_fault
2.76% mmap [kernel.kallsyms] [k] find_get_page
After patch:
30.00% mmap mmap [.] main
23.78% mmap [kernel.kallsyms] [k] page_fault
5.52% mmap [kernel.kallsyms] [k] mem_cgroup_update_file_mapped
3.81% mmap [kernel.kallsyms] [k] unmap_vmas
3.26% mmap [kernel.kallsyms] [k] find_get_page
3.18% mmap [kernel.kallsyms] [k] __do_fault
3.03% mmap [kernel.kallsyms] [k] filemap_fault
2.40% mmap [kernel.kallsyms] [k] handle_mm_fault
2.40% mmap [kernel.kallsyms] [k] do_page_fault
This patch reduces memcg's cost to some extent.
(mem_cgroup_update_file_mapped is called by both of map/unmap)
Note: It seems some more improvements are required..but no idea.
maybe removing set/unset flag is required.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.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>
Presently memory cgroup accounts file-mapped by counter and flag. counter
is working in the same way with zone_stat but FileMapped flag only exists
in memcg (for helping move_account).
This flag can be updated wrongly in a case. Assume CPU0 and CPU1 and a
thread mapping a page on CPU0, another thread unmapping it on CPU1.
CPU0 CPU1
rmv rmap (mapcount 1->0)
add rmap (mapcount 0->1)
lock_page_cgroup()
memcg counter+1 (some delay)
set MAPPED FLAG.
unlock_page_cgroup()
lock_page_cgroup()
memcg counter-1
clear MAPPED flag
In the above sequence counter is properly updated but FLAG is not. This
means that representing a state by a flag which is maintained by counter
needs some special care.
To handle this, when clearing a flag, this patch check mapcount directly
and clear the flag only when mapcount == 0. (if mapcount >0, someone will
make it to zero later and flag will be cleared.)
Reverse case, dec-after-inc cannot be a problem because page_table_lock()
works well for it. (IOW, to make above sequence, 2 processes should touch
the same page at once with map/unmap.)
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It appears i386 uses kmap_atomic infrastructure regardless of
CONFIG_HIGHMEM which results in a compile error when highmem is disabled.
Cure this by providing the needed few bits for both CONFIG_HIGHMEM and
CONFIG_X86_32.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Save the current exception frame pointer in the thread_info struct rather than
in a global variable as the latter makes SMP tricky, especially when preemption
is also enabled.
This also replaces __frame with current_frame() and rearranges header file
inclusions to make it all compile.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
split invalidate_inodes()
fs: skip I_FREEING inodes in writeback_sb_inodes
fs: fold invalidate_list into invalidate_inodes
fs: do not drop inode_lock in dispose_list
fs: inode split IO and LRU lists
fs: switch bdev inode bdi's correctly
fs: fix buffer invalidation in invalidate_list
fsnotify: use dget_parent
smbfs: use dget_parent
exportfs: use dget_parent
fs: use RCU read side protection in d_validate
fs: clean up dentry lru modification
fs: split __shrink_dcache_sb
fs: improve DCACHE_REFERENCED usage
fs: use percpu counter for nr_dentry and nr_dentry_unused
fs: simplify __d_free
fs: take dcache_lock inside __d_path
fs: do not assign default i_ino in new_inode
fs: introduce a per-cpu last_ino allocator
new helper: ihold()
...
PF_FLUSHER is only ever set, not tested, remove it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After all that's what they are intended for.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the new {max,min}3 macros to save some cycles and bytes on the stack.
This patch substitutes trivial nested macros with their counterpart.
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Joe Perches <joe@perches.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If not_managed is true all pages will be putback to lru, so break the loop
earlier to skip other pages isolate.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__test_page_isolated_in_pageblock() returns 1 if all pages in the range
are isolated, so fix the comment. Variable `pfn' will be initialised in
the following loop so remove it.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
page_order() is called by memory hotplug's user interface to check the
section is removable or not. (is_mem_section_removable())
It calls page_order() withoug holding zone->lock.
So, even if the caller does
if (PageBuddy(page))
ret = page_order(page) ...
The caller may hit BUG_ON().
For fixing this, there are 2 choices.
1. add zone->lock.
2. remove BUG_ON().
is_mem_section_removable() is used for some "advice" and doesn't need to
be 100% accurate. This is_removable() can be called via user program..
We don't want to take this important lock for long by user's request. So,
this patch removes BUG_ON().
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add missing spin_lock() of the page_table_lock before an error return in
hugetlb_cow(). Callers of hugtelb_cow() expect it to be held upon return.
Signed-off-by: Dean Nelson <dnelson@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The vma returned by find_vma does not necessarily include the target
address. If this happens the code tries to follow a page outside of any
vma and returns ENOENT instead of EFAULT.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
System management wants to subscribe to changes in swap configuration.
Make /proc/swaps pollable like /proc/mounts.
[akpm@linux-foundation.org: document proc_poll_event]
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Greg KH <greg@kroah.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add vzalloc() and vzalloc_node() to encapsulate the
vmalloc-then-memset-zero operation.
Use __GFP_ZERO to zero fill the allocated memory.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes following warning from sparse:
mm/vmstat.c:466:5: warning: symbol 'fragmentation_index' was not declared. Should it be static?
[akpm@linux-foundation.org: move the include to top-of-file]
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
s_start() and s_stop() grab/release vmlist_lock but were missing proper
annotations. Add them.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename redundant 'tmp' to fix following sparse warnings:
mm/vmalloc.c:296:34: warning: symbol 'tmp' shadows an earlier one
mm/vmalloc.c:293:24: originally declared here
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make anon_vma_chain_free() static. It is called only in rmap.c and the
corresponding alloc function is already static.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page_check_address() conditionally grabs *@ptlp in case of returning
non-NULL. Rename and wrap it using __cond_lock() removes following
warnings from sparse:
mm/rmap.c:472:9: warning: context imbalance in 'page_mapped_in_vma' - unexpected unlock
mm/rmap.c:524:9: warning: context imbalance in 'page_referenced_one' - unexpected unlock
mm/rmap.c:706:9: warning: context imbalance in 'page_mkclean_one' - unexpected unlock
mm/rmap.c:1066:9: warning: context imbalance in 'try_to_unmap_one' - unexpected unlock
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page_lock_anon_vma() conditionally grabs RCU and anon_vma lock but
page_unlock_anon_vma() releases them unconditionally. This leads sparse
to complain about context imbalance. Annotate them.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The follow_pte() conditionally grabs *@ptlp in case of returning 0.
Rename and wrap it using __cond_lock() removes following warnings:
mm/memory.c:2337:9: warning: context imbalance in 'do_wp_page' - unexpected unlock
mm/memory.c:3142:19: warning: context imbalance in 'handle_mm_fault' - different lock contexts for basic block
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The do_wp_page() releases @ptl but was missing proper annotation. Add it.
This removes following warnings from sparse:
mm/memory.c:2337:9: warning: context imbalance in 'do_wp_page' - unexpected unlock
mm/memory.c:3142:19: warning: context imbalance in 'handle_mm_fault' - different lock contexts for basic block
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The get_locked_pte() conditionally grabs 'ptl' in case of returning
non-NULL. This leads sparse to complain about context imbalance. Rename
and wrap it using __cond_lock() to make sparse happy.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes following warning from sparse:
mm/page_alloc.c:1934:9: warning: restricted gfp_t degrades to integer
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'end' shadows earlier one and is not necessary at all. Remove it and use
'pos' instead. This removes following sparse warnings:
mm/filemap.c:2180:24: warning: symbol 'end' shadows an earlier one
mm/filemap.c:2132:25: originally declared here
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This change reduces mmap_sem hold times that are caused by waiting for
disk transfers when accessing file mapped VMAs.
It introduces the VM_FAULT_ALLOW_RETRY flag, which indicates that the call
site wants mmap_sem to be released if blocking on a pending disk transfer.
In that case, filemap_fault() returns the VM_FAULT_RETRY status bit and
do_page_fault() will then re-acquire mmap_sem and retry the page fault.
It is expected that the retry will hit the same page which will now be
cached, and thus it will complete with a low mmap_sem hold time.
Tests:
- microbenchmark: thread A mmaps a large file and does random read accesses
to the mmaped area - achieves about 55 iterations/s. Thread B does
mmap/munmap in a loop at a separate location - achieves 55 iterations/s
before, 15000 iterations/s after.
- We are seeing related effects in some applications in house, which show
significant performance regressions when running without this change.
[akpm@linux-foundation.org: fix warning & crash]
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Ying Han <yinghan@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a single location where filemap_fault() locks the desired page.
There used to be two such places, depending if the initial find_get_page()
was successful or not.
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Ying Han <yinghan@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Buggy drivers (e.g. fsl_udc) could call dma_pool_alloc from atomic
context with GFP_KERNEL. In most instances, the first pool_alloc_page
call would succeed and the sleeping functions would never be called. This
allowed the buggy drivers to slip through the cracks.
Add a might_sleep_if() checking for __GFP_WAIT in flags.
Signed-off-by: Dima Zavin <dima@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since we no longer need to provide KM_type, the whole pte_*map_nested()
API is now redundant, remove it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Keep the current interface but ignore the KM_type and use a stack based
approach.
The advantage is that we get rid of crappy code like:
#define __KM_PTE \
(in_nmi() ? KM_NMI_PTE : \
in_irq() ? KM_IRQ_PTE : \
KM_PTE0)
and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.
The downside is that FRV kmap_atomic() gets more expensive.
For now we use a CPP trick suggested by Andrew:
#define kmap_atomic(page, args...) __kmap_atomic(page)
to avoid having to touch all kmap_atomic() users in a single patch.
[ not compiled on:
- mn10300: the arch doesn't actually build with highmem to begin with ]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a page has PG_referenced, shrink_page_list() discards it only if it
is not dirty. This rule works fine if the backing filesystem is a regular
one. PG_dirty is a good signal that the page was used recently because
the flusher threads clean pages periodically. In addition, page writeback
is costlier than simple page discard.
However, when a page is on tmpfs this heuristic doesn't work because
flusher threads don't write back tmpfs pages. Consequently tmpfs pages
always rotate around the lru twice at least and adds unnecessary lru
churn. Simple tmpfs streaming io shouldn't cause large anonymous page
swap-out.
Remove this unncessary reclaim bonus of tmpfs pages.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The dirty_ratio was silently limited in global_dirty_limits() to >= 5%.
This is not a user expected behavior. And it's inconsistent with
calc_period_shift(), which uses the plain vm_dirty_ratio value.
Let's remove the internal bound.
At the same time, fix balance_dirty_pages() to work with the
dirty_thresh=0 case. This allows applications to proceed when
dirty+writeback pages are all cleaned.
And ">" fits with the name "exceeded" better than ">=" does. Neil thinks
it is an aesthetic improvement as well as a functional one :)
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>
Proposed-by: Con Kolivas <kernel@kolivas.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michael Rubin <mrubin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If congestion_wait() is called with no BDI congested, the caller will
sleep for the full timeout and this may be an unnecessary sleep. This
patch adds a wait_iff_congested() that checks congestion and only sleeps
if a BDI is congested else, it calls cond_resched() to ensure the caller
is not hogging the CPU longer than its quota but otherwise will not sleep.
This is aimed at reducing some of the major desktop stalls reported during
IO. For example, while kswapd is operating, it calls congestion_wait()
but it could just have been reclaiming clean page cache pages with no
congestion. Without this patch, it would sleep for a full timeout but
after this patch, it'll just call schedule() if it has been on the CPU too
long. Similar logic applies to direct reclaimers that are not making
enough progress.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
isolate_lru_pages() does not just isolate LRU tail pages, but also
isolates neighbour pages of the eviction page. The neighbour search does
not stop even if neighbours cannot be isolated which is excessive as the
lumpy reclaim will no longer result in a successful higher order
allocation. This patch stops the PFN neighbour pages if an isolation
fails and moves on to the next block.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After synchrounous lumpy reclaim, the page_list is guaranteed to not have
active pages as page activation in shrink_page_list() disables lumpy
reclaim. Remove the dead code.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shrink_page_list() can decide to give up reclaiming a page under a
number of conditions such as
1. trylock_page() failure
2. page is unevictable
3. zone reclaim and page is mapped
4. PageWriteback() is true
5. page is swapbacked and swap is full
6. add_to_swap() failure
7. page is dirty and gfpmask don't have GFP_IO, GFP_FS
8. page is pinned
9. IO queue is congested
10. pageout() start IO, but not finished
With lumpy reclaim, failures result in entering synchronous lumpy reclaim
but this can be unnecessary. In cases (2), (3), (5), (6), (7) and (8),
there is no point retrying. This patch causes lumpy reclaim to abort when
it is known it will fail.
Case (9) is more interesting. current behavior is,
1. start shrink_page_list(async)
2. found queue_congested()
3. skip pageout write
4. still start shrink_page_list(sync)
5. wait on a lot of pages
6. again, found queue_congested()
7. give up pageout write again
So, it's useless time wasting. However, just skipping page reclaim is
also notgood as x86 allocating a huge page needs 512 pages for example.
It can have more dirty pages than queue congestion threshold (~=128).
After this patch, pageout() behaves as follows;
- If order > PAGE_ALLOC_COSTLY_ORDER
Ignore queue congestion always.
- If order <= PAGE_ALLOC_COSTLY_ORDER
skip write page and disable lumpy reclaim.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
congestion_wait() means "wait until queue congestion is cleared".
However, synchronous lumpy reclaim does not need this congestion_wait() as
shrink_page_list(PAGEOUT_IO_SYNC) uses wait_on_page_writeback() and it
provides the necessary waiting.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is strong evidence to indicate a lot of time is being spent in
congestion_wait(), some of it unnecessarily. This patch adds a tracepoint
for congestion_wait to record when congestion_wait() was called, how long
the timeout was for and how long it actually slept.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There have been numerous reports of stalls that pointed at the problem
being somewhere in the VM. There are multiple roots to the problems which
means dealing with any of the root problems in isolation is tricky to
justify on their own and they would still need integration testing. This
patch series puts together two different patch sets which in combination
should tackle some of the root causes of latency problems being reported.
Patch 1 adds a tracepoint for shrink_inactive_list. For this series, the
most important results is being able to calculate the scanning/reclaim
ratio as a measure of the amount of work being done by page reclaim.
Patch 2 accounts for time spent in congestion_wait.
Patches 3-6 were originally developed by Kosaki Motohiro but reworked for
this series. It has been noted that lumpy reclaim is far too aggressive
and trashes the system somewhat. As SLUB uses high-order allocations, a
large cost incurred by lumpy reclaim will be noticeable. It was also
reported during transparent hugepage support testing that lumpy reclaim
was trashing the system and these patches should mitigate that problem
without disabling lumpy reclaim.
Patch 7 adds wait_iff_congested() and replaces some callers of
congestion_wait(). wait_iff_congested() only sleeps if there is a BDI
that is currently congested. Patch 8 notes that any BDI being congested
is not necessarily a problem because there could be multiple BDIs of
varying speeds and numberous zones. It attempts to track when a zone
being reclaimed contains many pages backed by a congested BDI and if so,
reclaimers wait on the congestion queue.
I ran a number of tests with monitoring on X86, X86-64 and PPC64. Each
machine had 3G of RAM and the CPUs were
X86: Intel P4 2-core
X86-64: AMD Phenom 4-core
PPC64: PPC970MP
Each used a single disk and the onboard IO controller. Dirty ratio was
left at 20. I'm just going to report for X86-64 and PPC64 in a vague
attempt to keep this report short. Four kernels were tested each based on
v2.6.36-rc4
traceonly-v2r2: Patches 1 and 2 to instrument vmscan reclaims and congestion_wait
lowlumpy-v2r3: Patches 1-6 to test if lumpy reclaim is better
waitcongest-v2r3: Patches 1-7 to only wait on congestion
waitwriteback-v2r4: Patches 1-8 to detect when a zone is congested
nocongest-v1r5: Patches 1-3 for testing wait_iff_congestion
nodirect-v1r5: Patches 1-10 to disable filesystem writeback for better IO
The tests run were as follows
kernbench
compile-based benchmark. Smoke test performance
sysbench
OLTP read-only benchmark. Will be re-run in the future as read-write
micro-mapped-file-stream
This is a micro-benchmark from Johannes Weiner that accesses a
large sparse-file through mmap(). It was configured to run in only
single-CPU mode but can be indicative of how well page reclaim
identifies suitable pages.
stress-highalloc
Tries to allocate huge pages under heavy load.
kernbench, iozone and sysbench did not report any performance regression
on any machine. sysbench did pressure the system lightly and there was
reclaim activity but there were no difference of major interest between
the kernels.
X86-64 micro-mapped-file-stream
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3 waitwriteback-v2r4
pgalloc_dma 1639.00 ( 0.00%) 667.00 (-145.73%) 1167.00 ( -40.45%) 578.00 (-183.56%)
pgalloc_dma32 2842410.00 ( 0.00%) 2842626.00 ( 0.01%) 2843043.00 ( 0.02%) 2843014.00 ( 0.02%)
pgalloc_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgsteal_dma 729.00 ( 0.00%) 85.00 (-757.65%) 609.00 ( -19.70%) 125.00 (-483.20%)
pgsteal_dma32 2338721.00 ( 0.00%) 2447354.00 ( 4.44%) 2429536.00 ( 3.74%) 2436772.00 ( 4.02%)
pgsteal_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgscan_kswapd_dma 1469.00 ( 0.00%) 532.00 (-176.13%) 1078.00 ( -36.27%) 220.00 (-567.73%)
pgscan_kswapd_dma32 4597713.00 ( 0.00%) 4503597.00 ( -2.09%) 4295673.00 ( -7.03%) 3891686.00 ( -18.14%)
pgscan_kswapd_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgscan_direct_dma 71.00 ( 0.00%) 134.00 ( 47.01%) 243.00 ( 70.78%) 352.00 ( 79.83%)
pgscan_direct_dma32 305820.00 ( 0.00%) 280204.00 ( -9.14%) 600518.00 ( 49.07%) 957485.00 ( 68.06%)
pgscan_direct_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pageoutrun 16296.00 ( 0.00%) 21254.00 ( 23.33%) 18447.00 ( 11.66%) 20067.00 ( 18.79%)
allocstall 443.00 ( 0.00%) 273.00 ( -62.27%) 513.00 ( 13.65%) 1568.00 ( 71.75%)
These are based on the raw figures taken from /proc/vmstat. It's a rough
measure of reclaim activity. Note that allocstall counts are higher
because we are entering direct reclaim more often as a result of not
sleeping in congestion. In itself, it's not necessarily a bad thing.
It's easier to get a view of what happened from the vmscan tracepoint
report.
FTrace Reclaim Statistics: vmscan
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3 waitwriteback-v2r4
Direct reclaims 443 273 513 1568
Direct reclaim pages scanned 305968 280402 600825 957933
Direct reclaim pages reclaimed 43503 19005 30327 117191
Direct reclaim write file async I/O 0 0 0 0
Direct reclaim write anon async I/O 0 3 4 12
Direct reclaim write file sync I/O 0 0 0 0
Direct reclaim write anon sync I/O 0 0 0 0
Wake kswapd requests 187649 132338 191695 267701
Kswapd wakeups 3 1 4 1
Kswapd pages scanned 4599269 4454162 4296815 3891906
Kswapd pages reclaimed 2295947 2428434 2399818 2319706
Kswapd reclaim write file async I/O 1 0 1 1
Kswapd reclaim write anon async I/O 59 187 41 222
Kswapd reclaim write file sync I/O 0 0 0 0
Kswapd reclaim write anon sync I/O 0 0 0 0
Time stalled direct reclaim (seconds) 4.34 2.52 6.63 2.96
Time kswapd awake (seconds) 11.15 10.25 11.01 10.19
Total pages scanned 4905237 4734564 4897640 4849839
Total pages reclaimed 2339450 2447439 2430145 2436897
%age total pages scanned/reclaimed 47.69% 51.69% 49.62% 50.25%
%age total pages scanned/written 0.00% 0.00% 0.00% 0.00%
%age file pages scanned/written 0.00% 0.00% 0.00% 0.00%
Percentage Time Spent Direct Reclaim 29.23% 19.02% 38.48% 20.25%
Percentage Time kswapd Awake 78.58% 78.85% 76.83% 79.86%
What is interesting here for nocongest in particular is that while direct
reclaim scans more pages, the overall number of pages scanned remains the
same and the ratio of pages scanned to pages reclaimed is more or less the
same. In other words, while we are sleeping less, reclaim is not doing
more work and as direct reclaim and kswapd is awake for less time, it
would appear to be doing less work.
FTrace Reclaim Statistics: congestion_wait
Direct number congest waited 87 196 64 0
Direct time congest waited 4604ms 4732ms 5420ms 0ms
Direct full congest waited 72 145 53 0
Direct number conditional waited 0 0 324 1315
Direct time conditional waited 0ms 0ms 0ms 0ms
Direct full conditional waited 0 0 0 0
KSwapd number congest waited 20 10 15 7
KSwapd time congest waited 1264ms 536ms 884ms 284ms
KSwapd full congest waited 10 4 6 2
KSwapd number conditional waited 0 0 0 0
KSwapd time conditional waited 0ms 0ms 0ms 0ms
KSwapd full conditional waited 0 0 0 0
The vanilla kernel spent 8 seconds asleep in direct reclaim and no time at
all asleep with the patches.
MMTests Statistics: duration
User/Sys Time Running Test (seconds) 10.51 10.73 10.6 11.66
Total Elapsed Time (seconds) 14.19 13.00 14.33 12.76
Overall, the tests completed faster. It is interesting to note that backing off further
when a zone is congested and not just a BDI was more efficient overall.
PPC64 micro-mapped-file-stream
pgalloc_dma 3024660.00 ( 0.00%) 3027185.00 ( 0.08%) 3025845.00 ( 0.04%) 3026281.00 ( 0.05%)
pgalloc_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgsteal_dma 2508073.00 ( 0.00%) 2565351.00 ( 2.23%) 2463577.00 ( -1.81%) 2532263.00 ( 0.96%)
pgsteal_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgscan_kswapd_dma 4601307.00 ( 0.00%) 4128076.00 ( -11.46%) 3912317.00 ( -17.61%) 3377165.00 ( -36.25%)
pgscan_kswapd_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgscan_direct_dma 629825.00 ( 0.00%) 971622.00 ( 35.18%) 1063938.00 ( 40.80%) 1711935.00 ( 63.21%)
pgscan_direct_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pageoutrun 27776.00 ( 0.00%) 20458.00 ( -35.77%) 18763.00 ( -48.04%) 18157.00 ( -52.98%)
allocstall 977.00 ( 0.00%) 2751.00 ( 64.49%) 2098.00 ( 53.43%) 5136.00 ( 80.98%)
Similar trends to x86-64. allocstalls are up but it's not necessarily bad.
FTrace Reclaim Statistics: vmscan
Direct reclaims 977 2709 2098 5136
Direct reclaim pages scanned 629825 963814 1063938 1711935
Direct reclaim pages reclaimed 75550 242538 150904 387647
Direct reclaim write file async I/O 0 0 0 2
Direct reclaim write anon async I/O 0 10 0 4
Direct reclaim write file sync I/O 0 0 0 0
Direct reclaim write anon sync I/O 0 0 0 0
Wake kswapd requests 392119 1201712 571935 571921
Kswapd wakeups 3 2 3 3
Kswapd pages scanned 4601307 4128076 3912317 3377165
Kswapd pages reclaimed 2432523 2318797 2312673 2144616
Kswapd reclaim write file async I/O 20 1 1 1
Kswapd reclaim write anon async I/O 57 132 11 121
Kswapd reclaim write file sync I/O 0 0 0 0
Kswapd reclaim write anon sync I/O 0 0 0 0
Time stalled direct reclaim (seconds) 6.19 7.30 13.04 10.88
Time kswapd awake (seconds) 21.73 26.51 25.55 23.90
Total pages scanned 5231132 5091890 4976255 5089100
Total pages reclaimed 2508073 2561335 2463577 2532263
%age total pages scanned/reclaimed 47.95% 50.30% 49.51% 49.76%
%age total pages scanned/written 0.00% 0.00% 0.00% 0.00%
%age file pages scanned/written 0.00% 0.00% 0.00% 0.00%
Percentage Time Spent Direct Reclaim 18.89% 20.65% 32.65% 27.65%
Percentage Time kswapd Awake 72.39% 80.68% 78.21% 77.40%
Again, a similar trend that the congestion_wait changes mean that direct
reclaim scans more pages but the overall number of pages scanned while
slightly reduced, are very similar. The ratio of scanning/reclaimed
remains roughly similar. The downside is that kswapd and direct reclaim
was awake longer and for a larger percentage of the overall workload.
It's possible there were big differences in the amount of time spent
reclaiming slab pages between the different kernels which is plausible
considering that the micro tests runs after fsmark and sysbench.
Trace Reclaim Statistics: congestion_wait
Direct number congest waited 845 1312 104 0
Direct time congest waited 19416ms 26560ms 7544ms 0ms
Direct full congest waited 745 1105 72 0
Direct number conditional waited 0 0 1322 2935
Direct time conditional waited 0ms 0ms 12ms 312ms
Direct full conditional waited 0 0 0 3
KSwapd number congest waited 39 102 75 63
KSwapd time congest waited 2484ms 6760ms 5756ms 3716ms
KSwapd full congest waited 20 48 46 25
KSwapd number conditional waited 0 0 0 0
KSwapd time conditional waited 0ms 0ms 0ms 0ms
KSwapd full conditional waited 0 0 0 0
The vanilla kernel spent 20 seconds asleep in direct reclaim and only
312ms asleep with the patches. The time kswapd spent congest waited was
also reduced by a large factor.
MMTests Statistics: duration
ser/Sys Time Running Test (seconds) 26.58 28.05 26.9 28.47
Total Elapsed Time (seconds) 30.02 32.86 32.67 30.88
With all patches applies, the completion times are very similar.
X86-64 STRESS-HIGHALLOC
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3waitwriteback-v2r4
Pass 1 82.00 ( 0.00%) 84.00 ( 2.00%) 85.00 ( 3.00%) 85.00 ( 3.00%)
Pass 2 90.00 ( 0.00%) 87.00 (-3.00%) 88.00 (-2.00%) 89.00 (-1.00%)
At Rest 92.00 ( 0.00%) 90.00 (-2.00%) 90.00 (-2.00%) 91.00 (-1.00%)
Success figures across the board are broadly similar.
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3waitwriteback-v2r4
Direct reclaims 1045 944 886 887
Direct reclaim pages scanned 135091 119604 109382 101019
Direct reclaim pages reclaimed 88599 47535 47863 46671
Direct reclaim write file async I/O 494 283 465 280
Direct reclaim write anon async I/O 29357 13710 16656 13462
Direct reclaim write file sync I/O 154 2 2 3
Direct reclaim write anon sync I/O 14594 571 509 561
Wake kswapd requests 7491 933 872 892
Kswapd wakeups 814 778 731 780
Kswapd pages scanned 7290822 15341158 11916436 13703442
Kswapd pages reclaimed 3587336 3142496 3094392 3187151
Kswapd reclaim write file async I/O 91975 32317 28022 29628
Kswapd reclaim write anon async I/O 1992022 789307 829745 849769
Kswapd reclaim write file sync I/O 0 0 0 0
Kswapd reclaim write anon sync I/O 0 0 0 0
Time stalled direct reclaim (seconds) 4588.93 2467.16 2495.41 2547.07
Time kswapd awake (seconds) 2497.66 1020.16 1098.06 1176.82
Total pages scanned 7425913 15460762 12025818 13804461
Total pages reclaimed 3675935 3190031 3142255 3233822
%age total pages scanned/reclaimed 49.50% 20.63% 26.13% 23.43%
%age total pages scanned/written 28.66% 5.41% 7.28% 6.47%
%age file pages scanned/written 1.25% 0.21% 0.24% 0.22%
Percentage Time Spent Direct Reclaim 57.33% 42.15% 42.41% 42.99%
Percentage Time kswapd Awake 43.56% 27.87% 29.76% 31.25%
Scanned/reclaimed ratios again look good with big improvements in
efficiency. The Scanned/written ratios also look much improved. With a
better scanned/written ration, there is an expectation that IO would be
more efficient and indeed, the time spent in direct reclaim is much
reduced by the full series and kswapd spends a little less time awake.
Overall, indications here are that allocations were happening much faster
and this can be seen with a graph of the latency figures as the
allocations were taking place
http://www.csn.ul.ie/~mel/postings/vmscanreduce-20101509/highalloc-interlatency-hydra-mean.ps
FTrace Reclaim Statistics: congestion_wait
Direct number congest waited 1333 204 169 4
Direct time congest waited 78896ms 8288ms 7260ms 200ms
Direct full congest waited 756 92 69 2
Direct number conditional waited 0 0 26 186
Direct time conditional waited 0ms 0ms 0ms 2504ms
Direct full conditional waited 0 0 0 25
KSwapd number congest waited 4 395 227 282
KSwapd time congest waited 384ms 25136ms 10508ms 18380ms
KSwapd full congest waited 3 232 98 176
KSwapd number conditional waited 0 0 0 0
KSwapd time conditional waited 0ms 0ms 0ms 0ms
KSwapd full conditional waited 0 0 0 0
KSwapd full conditional waited 318 0 312 9
Overall, the time spent speeping is reduced. kswapd is still hitting
congestion_wait() but that is because there are callers remaining where it
wasn't clear in advance if they should be changed to wait_iff_congested()
or not. Overall the sleep imes are reduced though - from 79ish seconds to
about 19.
MMTests Statistics: duration
User/Sys Time Running Test (seconds) 3415.43 3386.65 3388.39 3377.5
Total Elapsed Time (seconds) 5733.48 3660.33 3689.41 3765.39
With the full series, the time to complete the tests are reduced by 30%
PPC64 STRESS-HIGHALLOC
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3waitwriteback-v2r4
Pass 1 17.00 ( 0.00%) 34.00 (17.00%) 38.00 (21.00%) 43.00 (26.00%)
Pass 2 25.00 ( 0.00%) 37.00 (12.00%) 42.00 (17.00%) 46.00 (21.00%)
At Rest 49.00 ( 0.00%) 43.00 (-6.00%) 45.00 (-4.00%) 51.00 ( 2.00%)
Success rates there are *way* up particularly considering that the 16MB
huge pages on PPC64 mean that it's always much harder to allocate them.
FTrace Reclaim Statistics: vmscan
stress-highalloc stress-highalloc stress-highalloc stress-highalloc
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3waitwriteback-v2r4
Direct reclaims 499 505 564 509
Direct reclaim pages scanned 223478 41898 51818 45605
Direct reclaim pages reclaimed 137730 21148 27161 23455
Direct reclaim write file async I/O 399 136 162 136
Direct reclaim write anon async I/O 46977 2865 4686 3998
Direct reclaim write file sync I/O 29 0 1 3
Direct reclaim write anon sync I/O 31023 159 237 239
Wake kswapd requests 420 351 360 326
Kswapd wakeups 185 294 249 277
Kswapd pages scanned 15703488 16392500 17821724 17598737
Kswapd pages reclaimed 5808466 2908858 3139386 3145435
Kswapd reclaim write file async I/O 159938 18400 18717 13473
Kswapd reclaim write anon async I/O 3467554 228957 322799 234278
Kswapd reclaim write file sync I/O 0 0 0 0
Kswapd reclaim write anon sync I/O 0 0 0 0
Time stalled direct reclaim (seconds) 9665.35 1707.81 2374.32 1871.23
Time kswapd awake (seconds) 9401.21 1367.86 1951.75 1328.88
Total pages scanned 15926966 16434398 17873542 17644342
Total pages reclaimed 5946196 2930006 3166547 3168890
%age total pages scanned/reclaimed 37.33% 17.83% 17.72% 17.96%
%age total pages scanned/written 23.27% 1.52% 1.94% 1.43%
%age file pages scanned/written 1.01% 0.11% 0.11% 0.08%
Percentage Time Spent Direct Reclaim 44.55% 35.10% 41.42% 36.91%
Percentage Time kswapd Awake 86.71% 43.58% 52.67% 41.14%
While the scanning rates are slightly up, the scanned/reclaimed and
scanned/written figures are much improved. The time spent in direct
reclaim and with kswapd are massively reduced, mostly by the lowlumpy
patches.
FTrace Reclaim Statistics: congestion_wait
Direct number congest waited 725 303 126 3
Direct time congest waited 45524ms 9180ms 5936ms 300ms
Direct full congest waited 487 190 52 3
Direct number conditional waited 0 0 200 301
Direct time conditional waited 0ms 0ms 0ms 1904ms
Direct full conditional waited 0 0 0 19
KSwapd number congest waited 0 2 23 4
KSwapd time congest waited 0ms 200ms 420ms 404ms
KSwapd full congest waited 0 2 2 4
KSwapd number conditional waited 0 0 0 0
KSwapd time conditional waited 0ms 0ms 0ms 0ms
KSwapd full conditional waited 0 0 0 0
Not as dramatic a story here but the time spent asleep is reduced and we
can still see what wait_iff_congested is going to sleep when necessary.
MMTests Statistics: duration
User/Sys Time Running Test (seconds) 12028.09 3157.17 3357.79 3199.16
Total Elapsed Time (seconds) 10842.07 3138.72 3705.54 3229.85
The time to complete this test goes way down. With the full series, we
are allocating over twice the number of huge pages in 30% of the time and
there is a corresponding impact on the allocation latency graph available
at.
http://www.csn.ul.ie/~mel/postings/vmscanreduce-20101509/highalloc-interlatency-powyah-mean.ps
This patch:
Add a trace event for shrink_inactive_list() and updates the sample
postprocessing script appropriately. It can be used to determine how many
pages were reclaimed and for non-lumpy reclaim where exactly the pages
were reclaimed from.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
`priority' cannot be negative here. And the comment is obsolete.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel already exposes the user desired thresholds in /proc/sys/vm
with dirty_background_ratio and background_ratio. But the kernel may
alter the number requested without giving the user any indication that is
the case.
Knowing the actual ratios the kernel is honoring can help app developers
understand how their buffered IO will be sent to the disk.
$ grep threshold /proc/vmstat
nr_dirty_threshold 409111
nr_dirty_background_threshold 818223
Signed-off-by: Michael Rubin <mrubin@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To help developers and applications gain visibility into writeback
behaviour adding two entries to vm_stat_items and /proc/vmstat. This will
allow us to track the "written" and "dirtied" counts.
# grep nr_dirtied /proc/vmstat
nr_dirtied 3747
# grep nr_written /proc/vmstat
nr_written 3618
Signed-off-by: Michael Rubin <mrubin@google.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To help developers and applications gain visibility into writeback
behaviour this patch adds two counters to /proc/vmstat.
# grep nr_dirtied /proc/vmstat
nr_dirtied 3747
# grep nr_written /proc/vmstat
nr_written 3618
These entries allow user apps to understand writeback behaviour over time
and learn how it is impacting their performance. Currently there is no
way to inspect dirty and writeback speed over time. It's not possible for
nr_dirty/nr_writeback.
These entries are necessary to give visibility into writeback behaviour.
We have /proc/diskstats which lets us understand the io in the block
layer. We have blktrace for more in depth understanding. We have
e2fsprogs and debugsfs to give insight into the file systems behaviour,
but we don't offer our users the ability understand what writeback is
doing. There is no way to know how active it is over the whole system, if
it's falling behind or to quantify it's efforts. With these values
exported users can easily see how much data applications are sending
through writeback and also at what rates writeback is processing this
data. Comparing the rates of change between the two allow developers to
see when writeback is not able to keep up with incoming traffic and the
rate of dirty memory being sent to the IO back end. This allows folks to
understand their io workloads and track kernel issues. Non kernel
engineers at Google often use these counters to solve puzzling performance
problems.
Patch #4 adds a pernode vmstat file with nr_dirtied and nr_written
Patch #5 add writeback thresholds to /proc/vmstat
Currently these values are in debugfs. But they should be promoted to
/proc since they are useful for developers who are writing databases
and file servers and are not debugging the kernel.
The output is as below:
# grep threshold /proc/vmstat
nr_pages_dirty_threshold 409111
nr_pages_dirty_background_threshold 818223
This patch:
This allows code outside of the mm core to safely manipulate page
writeback state and not worry about the other accounting. Not using these
routines means that some code will lose track of the accounting and we get
bugs.
Modify nilfs2 to use interface.
Signed-off-by: Michael Rubin <mrubin@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Jiro SEKIBA <jir@unicus.jp>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Function check_range may return ERR_PTR(...). Check for it.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ying Han reported that backing aging of anon pages in no swap system
causes unnecessary TLB flush.
When I sent a patch(69c8548175), I wanted this patch but Rik pointed out
and allowed aging of anon pages to give a chance to promote from inactive
to active LRU.
It has a two problem.
1) non-swap system
Never make sense to age anon pages.
2) swap configured but still doesn't swapon
It doesn't make sense to age anon pages until swap-on time. But it's
arguable. If we have aged anon pages by swapon, VM have moved anon pages
from active to inactive. And in the time swapon by admin, the VM can't
reclaim hot pages so we can protect hot pages swapout.
But let's think about it. When does swap-on happen? It depends on admin.
we can't expect it. Nonetheless, we have done aging of anon pages to
protect hot pages swapout. It means we lost run time overhead when below
high watermark but gain hot page swap-[in/out] overhead when VM decide
swapout. Is it true? Let's think more detail. We don't promote anon
pages in case of non-swap system. So even though VM does aging of anon
pages, the pages would be in inactive LRU for a long time. It means many
of pages in there would mark access bit again. So access bit hot/code
separation would be pointless.
This patch prevents unnecessary anon pages demotion in not-yet-swapon and
non-configured swap system. Even, in non-configuared swap system
inactive_anon_is_low can be compiled out.
It could make side effect that hot anon pages could swap out when admin
does swap on. But I think sooner or later it would be steady state. So
it's not a big problem.
We could lose someting but gain more thing(TLB flush and unnecessary
function call to demote anon pages).
Signed-off-by: Ying Han <yinghan@google.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, sysfs interface of memory hotplug shows whether the section is
removable or not. But it checks only migrateype of pages and doesn't
check details of cluster of pages.
Next, memory hotplug's set_migratetype_isolate() has the same kind of
check, too.
This patch adds the function __count_unmovable_pages() and makes above 2
checks to use the same logic. Then, is_removable and hotremove code uses
the same logic. No changes in the hotremove logic itself.
TODO: need to find a way to check RECLAMABLE. But, considering bit,
calling shrink_slab() against a range before starting memory hotremove
sounds better. If so, this patch's logic doesn't need to be changed.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reported-by: Michal Hocko <mhocko@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Even if notifier cannot find any pages, it doesn't mean no pages are
available...And, if there are no notifiers registered, this condition will
be always true and memory hotplug will show -EBUSY.
This is a bug but not critical.
In most case, a pageblock which will be offlined is MIGRATE_MOVABLE This
"notifier" is called only when the pageblock is _not_ MIGRATE_MOVABLE.
But if not MIGRATE_MOVABLE, it's common case that memory hotplug will
fail. So, no one notice this bug.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Presently update_nr_listpages() doesn't have a role. That's because lists
passed is always empty just after calling migrate_pages. The
migrate_pages cleans up page list which have failed to migrate before
returning by aaa994b3.
[PATCH] page migration: handle freeing of pages in migrate_pages()
Do not leave pages on the lists passed to migrate_pages(). Seems that we will
not need any postprocessing of pages. This will simplify the handling of
pages by the callers of migrate_pages().
At that time, we thought we don't need any postprocessing of pages. But
the situation is changed. The compaction need to know the number of
failed to migrate for COMPACTPAGEFAILED stat
This patch makes new rule for caller of migrate_pages to call
putback_lru_pages. So caller need to clean up the lists so it has a
chance to postprocess the pages. [suggested by Christoph Lameter]
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.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>
Non-NUMA systems do never create these files anyway, since they are only
created by driver subsystem when NUMA is configured.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes more dead code that was somehow missed by commit 0d99519efe
(writeback: remove unused nonblocking and congestion checks). There are
no behavior change except for the removal of two entries from one of the
ext4 tracing interface.
The nonblocking checks in ->writepages are no longer used because the
flusher now prefer to block on get_request_wait() than to skip inodes on
IO congestion. The latter will lead to more seeky IO.
The nonblocking checks in ->writepage are no longer used because it's
redundant with the WB_SYNC_NONE check.
We no long set ->nonblocking in VM page out and page migration, because
a) it's effectively redundant with WB_SYNC_NONE in current code
b) it's old semantic of "Don't get stuck on request queues" is mis-behavior:
that would skip some dirty inodes on congestion and page out others, which
is unfair in terms of LRU age.
Inspired by Christoph Hellwig. Thanks!
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: David Howells <dhowells@redhat.com>
Cc: Sage Weil <sage@newdream.net>
Cc: Steve French <sfrench@samba.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's necessary to kill all threads that share an oom killed task's mm if
the goal is to lead to future memory freeing.
This patch reintroduces the code removed in 8c5cd6f3 (oom: oom_kill
doesn't kill vfork parent (or child)) since it is obsoleted.
It's now guaranteed that any task passed to oom_kill_task() does not share
an mm with any thread that is unkillable. Thus, we're safe to issue a
SIGKILL to any thread sharing the same mm.
This is especially necessary to solve an mm->mmap_sem livelock issue
whereas an oom killed thread must acquire the lock in the exit path while
another thread is holding it in the page allocator while trying to
allocate memory itself (and will preempt the oom killer since a task was
already killed). Since tasks with pending fatal signals are now granted
access to memory reserves, the thread holding the lock may quickly
allocate and release the lock so that the oom killed task may exit.
This mainly is for threads that are cloned with CLONE_VM but not
CLONE_THREAD, so they are in a different thread group. Non-NPTL threads
exist in the wild and this change is necessary to prevent the livelock in
such cases. We care more about preventing the livelock than incurring the
additional tasklist in the oom killer when a task has been killed.
Systems that are sufficiently large to not want the tasklist scan in the
oom killer in the first place already have the option of enabling
/proc/sys/vm/oom_kill_allocating_task, which was designed specifically for
that purpose.
This code had existed in the oom killer for over eight years dating back
to the 2.4 kernel.
[akpm@linux-foundation.org: add nice comment]
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The oom killer's goal is to kill a memory-hogging task so that it may
exit, free its memory, and allow the current context to allocate the
memory that triggered it in the first place. Thus, killing a task is
pointless if other threads sharing its mm cannot be killed because of its
/proc/pid/oom_adj or /proc/pid/oom_score_adj value.
This patch checks whether any other thread sharing p->mm has an
oom_score_adj of OOM_SCORE_ADJ_MIN. If so, the thread cannot be killed
and oom_badness(p) returns 0, meaning it's unkillable.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a bug in commit 6dda9d55 ("page allocator: reduce fragmentation
in buddy allocator by adding buddies that are merging to the tail of the
free lists") that means a buddy at order MAX_ORDER is checked for merging.
A page of this order never exists so at times, an effectively random
piece of memory is being checked.
Alan Curry has reported that this is causing memory corruption in
userspace data on a PPC32 platform (http://lkml.org/lkml/2010/10/9/32).
It is not clear why this is happening. It could be a cache coherency
problem where pages mapped in both user and kernel space are getting
different cache lines due to the bad read from kernel space
(http://lkml.org/lkml/2010/10/13/179). It could also be that there are
some special registers being io-remapped at the end of the memmap array
and that a read has special meaning on them. Compiler bugs have been
ruled out because the assembly before and after the patch looks relatively
harmless.
This patch fixes the problem by ensuring we are not reading a possibly
invalid location of memory. It's not clear why the read causes corruption
but one way or the other it is a buggy read.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Corrado Zoccolo <czoccolo@gmail.com>
Reported-by: Alan Curry <pacman@kosh.dhis.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
scan_lru_pages returns pfn. So, it's type should be "unsigned long"
not "int".
Note: I guess this has been work until now because memory hotplug tester's
machine has not very big memory....
physical address < 32bit << PAGE_SHIFT.
Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The use of the same inode list structure (inode->i_list) for two
different list constructs with different lifecycles and purposes
makes it impossible to separate the locking of the different
operations. Therefore, to enable the separation of the locking of
the writeback and reclaim lists, split the inode->i_list into two
separate lists dedicated to their specific tracking functions.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves. For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Improve performance of the sske operation by using the nonquiescing
variant if the affected page has no mappings established. On machines
with no support for the new sske variant the mask bit will be ignored.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: (27 commits)
SLUB: Fix memory hotplug with !NUMA
slub: Move functions to reduce #ifdefs
slub: Enable sysfs support for !CONFIG_SLUB_DEBUG
SLUB: Optimize slab_free() debug check
slub: Move NUMA-related functions under CONFIG_NUMA
slub: Add lock release annotation
slub: Fix signedness warnings
slub: extract common code to remove objects from partial list without locking
SLUB: Pass active and inactive redzone flags instead of boolean to debug functions
slub: reduce differences between SMP and NUMA
Revert "Slub: UP bandaid"
percpu: clear memory allocated with the km allocator
percpu: use percpu allocator on UP too
percpu: reduce PCPU_MIN_UNIT_SIZE to 32k
vmalloc: pcpu_get/free_vm_areas() aren't needed on UP
SLUB: Fix merged slab cache names
Slub: UP bandaid
slub: fix SLUB_RESILIENCY_TEST for dynamic kmalloc caches
slub: Fix up missing kmalloc_cache -> kmem_cache_node case for memoryhotplug
slub: Add dummy functions for the !SLUB_DEBUG case
...
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (321 commits)
KVM: Drop CONFIG_DMAR dependency around kvm_iommu_map_pages
KVM: Fix signature of kvm_iommu_map_pages stub
KVM: MCE: Send SRAR SIGBUS directly
KVM: MCE: Add MCG_SER_P into KVM_MCE_CAP_SUPPORTED
KVM: fix typo in copyright notice
KVM: Disable interrupts around get_kernel_ns()
KVM: MMU: Avoid sign extension in mmu_alloc_direct_roots() pae root address
KVM: MMU: move access code parsing to FNAME(walk_addr) function
KVM: MMU: audit: check whether have unsync sps after root sync
KVM: MMU: audit: introduce audit_printk to cleanup audit code
KVM: MMU: audit: unregister audit tracepoints before module unloaded
KVM: MMU: audit: fix vcpu's spte walking
KVM: MMU: set access bit for direct mapping
KVM: MMU: cleanup for error mask set while walk guest page table
KVM: MMU: update 'root_hpa' out of loop in PAE shadow path
KVM: x86 emulator: Eliminate compilation warning in x86_decode_insn()
KVM: x86: Fix constant type in kvm_get_time_scale
KVM: VMX: Add AX to list of registers clobbered by guest switch
KVM guest: Move a printk that's using the clock before it's ready
KVM: x86: TSC catchup mode
...
This function is used by KVM to pin process's page in the atomic context.
Define the 'weak' function to avoid other architecture not support it
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: update comments to reflect that percpu allocations are always zero-filled
percpu: Optimize __get_cpu_var()
x86, percpu: Optimize this_cpu_ptr
percpu: clear memory allocated with the km allocator
percpu: fix build breakage on s390 and cleanup build configuration tests
percpu: use percpu allocator on UP too
percpu: reduce PCPU_MIN_UNIT_SIZE to 32k
vmalloc: pcpu_get/free_vm_areas() aren't needed on UP
Fixed up trivial conflicts in include/linux/percpu.h
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: remove in_workqueue_context()
workqueue: Clarify that schedule_on_each_cpu is synchronous
memory_hotplug: drop spurious calls to flush_scheduled_work()
shpchp: update workqueue usage
pciehp: update workqueue usage
isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr()
workqueue: add and use WQ_MEM_RECLAIM flag
workqueue: fix HIGHPRI handling in keep_working()
workqueue: add queue_work and activate_work trace points
workqueue: prepare for more tracepoints
workqueue: implement flush[_delayed]_work_sync()
workqueue: factor out start_flush_work()
workqueue: cleanup flush/cancel functions
workqueue: implement alloc_ordered_workqueue()
Fix up trivial conflict in fs/gfs2/main.c as per Tejun
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits)
xen-blkfront: disable barrier/flush write support
Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c
block: remove BLKDEV_IFL_WAIT
aic7xxx_old: removed unused 'req' variable
block: remove the BH_Eopnotsupp flag
block: remove the BLKDEV_IFL_BARRIER flag
block: remove the WRITE_BARRIER flag
swap: do not send discards as barriers
fat: do not send discards as barriers
ext4: do not send discards as barriers
jbd2: replace barriers with explicit flush / FUA usage
jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
jbd: replace barriers with explicit flush / FUA usage
nilfs2: replace barriers with explicit flush / FUA usage
reiserfs: replace barriers with explicit flush / FUA usage
gfs2: replace barriers with explicit flush / FUA usage
btrfs: replace barriers with explicit flush / FUA usage
xfs: replace barriers with explicit flush / FUA usage
block: pass gfp_mask and flags to sb_issue_discard
dm: convey that all flushes are processed as empty
...
* 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (74 commits)
x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S
xen: Cope with unmapped pages when initializing kernel pagetable
memblock, bootmem: Round pfn properly for memory and reserved regions
memblock: Annotate memblock functions with __init_memblock
memblock: Allow memblock_init to be called early
memblock/arm: Fix memblock_region_is_memory() typo
x86, memblock: Remove __memblock_x86_find_in_range_size()
memblock: Fix wraparound in find_region()
x86-32, memblock: Make add_highpages honor early reserved ranges
x86, memblock: Fix crashkernel allocation
arm, memblock: Fix the sparsemem build
memblock: Fix section mismatch warnings
powerpc, memblock: Fix memblock API change fallout
memblock, microblaze: Fix memblock API change fallout
x86: Remove old bootmem code
x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve
x86: Remove not used early_res code
x86, memblock: Replace e820_/_early string with memblock_
x86: Use memblock to replace early_res
x86, memblock: Use memblock_debug to control debug message print out
...
Fix up trivial conflicts in arch/x86/kernel/setup.c and kernel/Makefile
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-32, percpu: Correct the ordering of the percpu readmostly section
x86, mm: Enable ARCH_DMA_ADDR_T_64BIT with X86_64 || HIGHMEM64G
x86: Spread tlb flush vector between nodes
percpu: Introduce a read-mostly percpu API
x86, mm: Fix incorrect data type in vmalloc_sync_all()
x86, mm: Hold mm->page_table_lock while doing vmalloc_sync
x86, mm: Fix bogus whitespace in sync_global_pgds()
x86-32: Fix sparse warning for the __PHYSICAL_MASK calculation
x86, mm: Add RESERVE_BRK_ARRAY() helper
mm, x86: Saving vmcore with non-lazy freeing of vmas
x86, kdump: Change copy_oldmem_page() to use cached addressing
x86, mm: fix uninitialized addr in kernel_physical_mapping_init()
x86, kmemcheck: Remove double test
x86, mm: Make spurious_fault check explicitly check the PRESENT bit
x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes
x86, mm: Separate x86_64 vmalloc_sync_all() into separate functions
x86, mm: Avoid unnecessary TLB flush
lru_add_drain_all() uses schedule_on_each_cpu() which is synchronous.
There is no reason to call flush_scheduled_work() after
lru_add_drain_all(). Drop the spurious calls.
This is to prepare for the deprecation and removal of
flush_scheduled_work().
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reason for merge:
Forward-port urgent change to arch/x86/mm/srat_64.c to the memblock tree.
Resolved Conflicts:
arch/x86/mm/srat_64.c
Originally-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Stephen found
WARNING: mm/built-in.o(.text+0x25ab8): Section mismatch in reference from the function memblock_find_base() to the function .init.text:memblock_find_region()
The function memblock_find_base() references
the function __init memblock_find_region().
This is often because memblock_find_base lacks a __init
annotation or the annotation of memblock_find_region is wrong.
So let memblock_find_region() to use __init_memblock instead of __init
directly.
Also fix one function that did not have __init* to be __init_memblock.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4CB366B1.40405@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The Xen setup code needs to call memblock_x86_reserve_range() very early,
so allow it to initialize the memblock subsystem before doing so. The
second memblock_init() is ignored.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <4CACFDAD.3090900@goop.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
31bit s390 doesn't have huge pages and failed with:
> mm/migrate.c: In function 'remove_migration_pte':
> mm/migrate.c:143:3: error: implicit declaration of function 'pte_mkhuge'
> mm/migrate.c:143:7: error: incompatible types when assigning to type 'pte_t' from type 'int'
Put that code into a ifdef.
Reported by Heiko Carstens
Signed-off-by: Andi Kleen <ak@linux.intel.com>
We don't reply in other temporary failure cases and there were no
reports of replies happening. I think the original reason it was
added was also just an early bug, not an observation of the race.
So remove the loop for now, but keep a warning message.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
The addr_valid flag is the only flag in "to_kill" and it's slightly more
efficient to have it as char instead of a bitfield.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Now that only a few obscure messages are left as pr_debug disable
outputting of pr_debug in memory-failure.c by default.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Convert a lot of pr_debugs in memory-failure.c that are generally useful
to pr_info. It's reasonable to print at least one message why
offlining succeeded or failed by default.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Clean up and improve the overview comment in memory-failure.c
Tidy some grammar issues in other comments.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Pekka Enberg