3918 Commits

Author SHA1 Message Date
Al Viro
2c48b9c455 switch alloc_file() to passing struct path
... and have the caller grab both mnt and dentry; kill
leak in infiniband, while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16 12:16:42 -05:00
Al Viro
4b42af81f0 switch shmem_file_setup() to alloc_file()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16 12:16:40 -05:00
Bob Liu
aa20d489ce memcg: code clean, remove unused variable in mem_cgroup_resize_limit()
Variable `progress' isn't used in mem_cgroup_resize_limit() any more.
Remove it.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:08 -08:00
Daisuke Nishimura
9ab322caa3 memcg: remove memcg_tasklist
memcg_tasklist was introduced at commit 7f4d454d(memcg: avoid deadlock
caused by race between oom and cpuset_attach) instead of cgroup_mutex to
fix a deadlock problem.  The cgroup_mutex, which was removed by the
commit, in mem_cgroup_out_of_memory() was originally introduced at commit
c7ba5c9e (Memory controller: OOM handling).

IIUC, the intention of this cgroup_mutex was to prevent task move during
select_bad_process() so that situations like below can be avoided.

  Assume cgroup "foo" has exceeded its limit and is about to trigger oom.
  1. Process A, which has been in cgroup "baa" and uses large memory, is just
     moved to cgroup "foo". Process A can be the candidates for being killed.
  2. Process B, which has been in cgroup "foo" and uses large memory, is just
     moved from cgroup "foo". Process B can be excluded from the candidates for
     being killed.

But these race window exists anyway even if we hold a lock, because
__mem_cgroup_try_charge() decides wether it should trigger oom or not
outside of the lock.  So the original cgroup_mutex in
mem_cgroup_out_of_memory and thus current memcg_tasklist has no use.  And
IMHO, those races are not so critical for users.

This patch removes it and make codes simpler.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: 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>
2009-12-16 07:20:07 -08:00
Daisuke Nishimura
d31f56dbf8 memcg: avoid oom-killing innocent task in case of use_hierarchy
task_in_mem_cgroup(), which is called by select_bad_process() to check
whether a task can be a candidate for being oom-killed from memcg's limit,
checks "curr->use_hierarchy"("curr" is the mem_cgroup the task belongs
to).

But this check return true(it's false positive) when:

	<some path>/aa		use_hierarchy == 0	<- hitting limit
	  <some path>/aa/00	use_hierarchy == 1	<- the task belongs to

This leads to killing an innocent task in aa/00.  This patch is a fix for
this bug.  And this patch also fixes the arg for
mem_cgroup_print_oom_info().  We should print information of mem_cgroup
which the task being killed, not current, belongs to.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:07 -08:00
Daisuke Nishimura
57f9fd7d25 memcg: cleanup mem_cgroup_move_parent()
mem_cgroup_move_parent() calls try_charge first and cancel_charge on
failure.  IMHO, charge/uncharge(especially charge) is high cost operation,
so we should avoid it as far as possible.

This patch tries to delay try_charge in mem_cgroup_move_parent() by
re-ordering checks it does.

And this patch renames mem_cgroup_move_account() to
__mem_cgroup_move_account(), changes the return value of
__mem_cgroup_move_account() from int to void, and adds a new
wrapper(mem_cgroup_move_account()), which checks whether a @pc is valid
for moving account and calls __mem_cgroup_move_account().

This patch removes the last caller of trylock_page_cgroup(), so removes
its definition too.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:07 -08:00
Daisuke Nishimura
a3032a2c15 memcg: add mem_cgroup_cancel_charge()
There are some places calling both res_counter_uncharge() and css_put() to
cancel the charge and the refcnt we have got by mem_cgroup_tyr_charge().

This patch introduces mem_cgroup_cancel_charge() and call it in those
places.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:07 -08:00
KAMEZAWA Hiroyuki
d8046582d5 memcg: make memcg's file mapped consistent with global VM
In global VM, FILE_MAPPED is used but memcg uses MAPPED_FILE.  This makes
grep difficult.  Replace memcg's MAPPED_FILE with FILE_MAPPED

And in global VM, mapped shared memory is accounted into FILE_MAPPED.
But memcg doesn't. fix it.
Note:
  page_is_file_cache() just checks SwapBacked or not.
  So, we need to check PageAnon.

Cc: Balbir Singh <balbir@in.ibm.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: 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>
2009-12-16 07:20:07 -08:00
KAMEZAWA Hiroyuki
cdec2e4265 memcg: coalesce charging via percpu storage
This is a patch for coalescing access to res_counter at charging by percpu
caching.  At charge, memcg charges 64pages and remember it in percpu
cache.  Because it's cache, drain/flush if necessary.

This version uses public percpu area.
 2 benefits for using public percpu area.
 1. Sum of stocked charge in the system is limited to # of cpus
    not to the number of memcg. This shows better synchonization.
 2. drain code for flush/cpuhotplug is very easy (and quick)

The most important point of this patch is that we never touch res_counter
in fast path. The res_counter is system-wide shared counter which is modified
very frequently. We shouldn't touch it as far as we can for avoiding
false sharing.

On x86-64 8cpu server, I tested overheads of memcg at page fault by
running a program which does map/fault/unmap in a loop. Running
a task per a cpu by taskset and see sum of the number of page faults
in 60secs.

[without memcg config]
  40156968  page-faults              #      0.085 M/sec   ( +-   0.046% )
  27.67 cache-miss/faults

[root cgroup]
  36659599  page-faults              #      0.077 M/sec   ( +-   0.247% )
  31.58 cache miss/faults

[in a child cgroup]
  18444157  page-faults              #      0.039 M/sec   ( +-   0.133% )
  69.96 cache miss/faults

[ + coalescing uncharge patch]
  27133719  page-faults              #      0.057 M/sec   ( +-   0.155% )
  47.16 cache miss/faults

[ + coalescing uncharge patch + this patch ]
  34224709  page-faults              #      0.072 M/sec   ( +-   0.173% )
  34.69 cache miss/faults

Changelog (since Oct/2):
  - updated comments
  - replaced get_cpu_var() with __get_cpu_var() if possible.
  - removed mutex for system-wide drain. adds a counter instead of it.
  - removed CONFIG_HOTPLUG_CPU

Changelog (old):
  - rebased onto the latest mmotm
  - moved charge size check before __GFP_WAIT check for avoiding unnecesary
  - added asynchronous flush routine.
  - fixed bugs pointed out by Nishimura-san.

[akpm@linux-foundation.org: tweak comments]
[nishimura@mxp.nes.nec.co.jp: don't do INIT_WORK() repeatedly against the same work_struct]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: 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>
2009-12-16 07:20:07 -08:00
KAMEZAWA Hiroyuki
569b846df5 memcg: coalesce uncharge during unmap/truncate
In massive parallel enviroment, res_counter can be a performance
bottleneck.  One strong techinque to reduce lock contention is reducing
calls by coalescing some amount of calls into one.

Considering charge/uncharge chatacteristic,
	- charge is done one by one via demand-paging.
	- uncharge is done by
		- in chunk at munmap, truncate, exit, execve...
		- one by one via vmscan/paging.

It seems we have a chance to coalesce uncharges for improving scalability
at unmap/truncation.

This patch is a for coalescing uncharge.  For avoiding scattering memcg's
structure to functions under /mm, this patch adds memcg batch uncharge
information to the task.  A reason for per-task batching is for making use
of caller's context information.  We do batched uncharge (deleyed
uncharge) when truncation/unmap occurs but do direct uncharge when
uncharge is called by memory reclaim (vmscan.c).

The degree of coalescing depends on callers
  - at invalidate/trucate... pagevec size
  - at unmap ....ZAP_BLOCK_SIZE
(memory itself will be freed in this degree.)
Then, we'll not coalescing too much.

On x86-64 8cpu server, I tested overheads of memcg at page fault by
running a program which does map/fault/unmap in a loop. Running
a task per a cpu by taskset and see sum of the number of page faults
in 60secs.

[without memcg config]
  40156968  page-faults              #      0.085 M/sec   ( +-   0.046% )
  27.67 cache-miss/faults
[root cgroup]
  36659599  page-faults              #      0.077 M/sec   ( +-   0.247% )
  31.58 miss/faults
[in a child cgroup]
  18444157  page-faults              #      0.039 M/sec   ( +-   0.133% )
  69.96 miss/faults
[child with this patch]
  27133719  page-faults              #      0.057 M/sec   ( +-   0.155% )
  47.16 miss/faults

We can see some amounts of improvement.
(root cgroup doesn't affected by this patch)
Another patch for "charge" will follow this and above will be improved more.

Changelog(since 2009/10/02):
 - renamed filed of memcg_batch (as pages to bytes, memsw to memsw_bytes)
 - some clean up and commentary/description updates.
 - added initialize code to copy_process(). (possible bug fix)

Changelog(old):
 - fixed !CONFIG_MEM_CGROUP case.
 - rebased onto the latest mmotm + softlimit fix patches.
 - unified patch for callers
 - added commetns.
 - make ->do_batch as bool.
 - removed css_get() at el. We don't need it.

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>
2009-12-16 07:20:07 -08:00
Kirill A. Shutemov
cd9b45b78a memcg: fix memory.memsw.usage_in_bytes for root cgroup
A memory cgroup has a memory.memsw.usage_in_bytes file.  It shows the sum
of the usage of pages and swapents in the cgroup.  Presently the root
cgroup's memsw.usage_in_bytes shows the wrong value - the number of
swapents are not added.

So take MEM_CGROUP_STAT_SWAPOUT into account.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@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>
2009-12-16 07:20:07 -08:00
KAMEZAWA Hiroyuki
4365a5676f oom-kill: fix NUMA constraint check with nodemask
Fix node-oriented allocation handling in oom-kill.c I myself think of this
as a bugfix not as an ehnancement.

In these days, things are changed as
  - alloc_pages() eats nodemask as its arguments, __alloc_pages_nodemask().
  - mempolicy don't maintain its own private zonelists.
  (And cpuset doesn't use nodemask for __alloc_pages_nodemask())

So, current oom-killer's check function is wrong.

This patch does
  - check nodemask, if nodemask && nodemask doesn't cover all
    node_states[N_HIGH_MEMORY], this is CONSTRAINT_MEMORY_POLICY.
  - Scan all zonelist under nodemask, if it hits cpuset's wall
    this faiulre is from cpuset.
And
  - modifies the caller of out_of_memory not to call oom if __GFP_THISNODE.
    This doesn't change "current" behavior. If callers use __GFP_THISNODE
    it should handle "page allocation failure" by itself.

  - handle __GFP_NOFAIL+__GFP_THISNODE path.
    This is something like a FIXME but this gfpmask is not used now.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:19:57 -08:00
KOSAKI Motohiro
3b4798cbc1 oom-kill: show virtual size and rss information of the killed process
In a typical oom analysis scenario, we frequently want to know whether the
killed process has a memory leak or not at the first step.  This patch
adds vsz and rss information to the oom log to help this analysis.  To
save time for the debugging.

example:
===================================================================
rsyslogd invoked oom-killer: gfp_mask=0x201da, order=0, oom_adj=0
Pid: 1308, comm: rsyslogd Not tainted 2.6.32-rc6 #24
Call Trace:
[<ffffffff8132e35b>] ?_spin_unlock+0x2b/0x40
[<ffffffff810f186e>] oom_kill_process+0xbe/0x2b0

(snip)

492283 pages non-shared
Out of memory: kill process 2341 (memhog) score 527276 or a child
Killed process 2341 (memhog) vsz:1054552kB, anon-rss:970588kB, file-rss:4kB
===========================================================================
                             ^
                             |
                            here

[rientjes@google.com: fix race, add pid & comm to message]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:19:57 -08:00
Andi Kleen
f2c03debdf HWPOISON: Remove stray phrase in a comment
Better to have complete sentences.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:01 +01:00
Andi Kleen
12686d153a HWPOISON: Try to allocate migration page on the same node
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:01 +01:00
Andi Kleen
0d57eb8dfc HWPOISON: Don't do early filtering if filter is disabled
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:01 +01:00
Andi Kleen
afcf938ee0 HWPOISON: Add a madvise() injector for soft page offlining
Process based injection is much easier to handle for test programs,
who can first bring a page into a specific state and then test.
So add a new MADV_SOFT_OFFLINE to soft offline a page, similar
to the existing hard offline injector.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:00 +01:00
Andi Kleen
facb6011f3 HWPOISON: Add soft page offline support
This is a simpler, gentler variant of memory_failure() for soft page
offlining controlled from user space.  It doesn't kill anything, just
tries to invalidate and if that doesn't work migrate the
page away.

This is useful for predictive failure analysis, where a page has
a high rate of corrected errors, but hasn't gone bad yet. Instead
it can be offlined early and avoided.

The offlining is controlled from sysfs, including a new generic
entry point for hard page offlining for symmetry too.

We use the page isolate facility to prevent re-allocation
race. Normally this is only used by memory hotplug. To avoid
races with memory allocation I am using lock_system_sleep().
This avoids the situation where memory hotplug is about
to isolate a page range and then hwpoison undoes that work.
This is a big hammer currently, but the simplest solution
currently.

When the page is not free or LRU we try to free pages
from slab and other caches. The slab freeing is currently
quite dumb and does not try to focus on the specific slab
cache which might own the page. This could be potentially
improved later.

Thanks to Fengguang Wu and Haicheng Li for some fixes.

[Added fix from Andrew Morton to adapt to new migrate_pages prototype]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:00 +01:00
Andi Kleen
2326c467df HWPOISON: Undefine short-hand macros after use to avoid namespace conflict
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:00 +01:00
Andi Kleen
0474a60ec7 HWPOISON: Use new shake_page in memory_failure
shake_page handles more types of page caches than
the much simpler lru_add_drain_all:

- slab (quite inefficiently for now)
- any other caches with a shrinker callback
- per cpu page allocator pages
- per CPU LRU

Use this call to try to turn pages into free or LRU pages.
Then handle the case of the page becoming free after drain everything.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:00 +01:00
Andi Kleen
413f9efbc5 HWPOISON: mention HWPoison in Kconfig entry
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:00 +01:00
Andi Kleen
d15f107d97 HWPOISON: Use get_user_page_fast in hwpoison madvise
The previous version didn't take the mmap_sem before calling gup(),
which is racy.

Use get_user_pages_fast() instead which doesn't need any locks.
This is also faster of course, but then it doesn't really matter
because this is just a testing path.

Based on report from Nick Piggin.
Cc: npiggin@suse.de

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:00 +01:00
Haicheng Li
1bfe5febe3 HWPOISON: add an interface to switch off/on all the page filters
In some use cases, user doesn't need extra filtering. E.g. user program
can inject errors through madvise syscall to its own pages, however it
might not know what the page state exactly is or which inode the page
belongs to.

So introduce an one-off interface "corrupt-filter-enable".

Echo 0 to switch off page filters, and echo 1 to switch on the filters.
[AK: changed default to 0]

Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:59 +01:00
Andi Kleen
4fd466eb46 HWPOISON: add memory cgroup filter
The hwpoison test suite need to inject hwpoison to a collection of
selected task pages, and must not touch pages not owned by them and
thus kill important system processes such as init. (But it's OK to
mis-hwpoison free/unowned pages as well as shared clean pages.
Mis-hwpoison of shared dirty pages will kill all tasks, so the test
suite will target all or non of such tasks in the first place.)

The memory cgroup serves this purpose well. We can put the target
processes under the control of a memory cgroup, and tell the hwpoison
injection code to only kill pages associated with some active memory
cgroup.

The prerequisite for doing hwpoison stress tests with mem_cgroup is,
the mem_cgroup code tracks task pages _accurately_ (unless page is
locked).  Which we believe is/should be true.

The benefits are simplification of hwpoison injector code. Also the
mem_cgroup code will automatically be tested by hwpoison test cases.

The alternative interfaces pin-pfn/unpin-pfn can also delegate the
(process and page flags) filtering functions reliably to user space.
However prototype implementation shows that this scheme adds more
complexity than we wanted.

Example test case:

	mkdir /cgroup/hwpoison

	usemem -m 100 -s 1000 &
	echo `jobs -p` > /cgroup/hwpoison/tasks

	memcg_ino=$(ls -id /cgroup/hwpoison | cut -f1 -d' ')
	echo $memcg_ino > /debug/hwpoison/corrupt-filter-memcg

	page-types -p `pidof init`   --hwpoison  # shall do nothing
	page-types -p `pidof usemem` --hwpoison  # poison its pages

[AK: Fix documentation]
[Add fix for problem noticed by Li Zefan <lizf@cn.fujitsu.com>;
dentry in the css could be NULL]

CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
CC: Hugh Dickins <hugh.dickins@tiscali.co.uk>
CC: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
CC: Balbir Singh <balbir@linux.vnet.ibm.com>
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Li Zefan <lizf@cn.fujitsu.com>
CC: Paul Menage <menage@google.com>
CC: Nick Piggin <npiggin@suse.de>
CC: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:59 +01:00
Wu Fengguang
d324236b33 memcg: add accessor to mem_cgroup.css
So that an outside user can free the reference count grabbed by
try_get_mem_cgroup_from_page().

CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
CC: Hugh Dickins <hugh.dickins@tiscali.co.uk>
CC: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
CC: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:59 +01:00
Wu Fengguang
e42d9d5d47 memcg: rename and export try_get_mem_cgroup_from_page()
So that the hwpoison injector can get mem_cgroup for arbitrary page
and thus know whether it is owned by some mem_cgroup task(s).

[AK: Merged with latest git tree]

CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
CC: Hugh Dickins <hugh.dickins@tiscali.co.uk>
CC: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
CC: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:59 +01:00
Wu Fengguang
478c5ffc0b HWPOISON: add page flags filter
When specified, only poison pages if ((page_flags & mask) == value).

-       corrupt-filter-flags-mask
-       corrupt-filter-flags-value

This allows stress testing of many kinds of pages.

Strictly speaking, the buddy pages requires taking zone lock, to avoid
setting PG_hwpoison on a "was buddy but now allocated to someone" page.
However we can just do nothing because we set PG_locked in the beginning,
this prevents the page allocator from allocating it to someone. (It will
BUG() on the unexpected PG_locked, which is fine for hwpoison testing.)

[AK: Add select PROC_PAGE_MONITOR to satisfy dependency]

CC: Nick Piggin <npiggin@suse.de>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:59 +01:00
Wu Fengguang
31d3d3484f HWPOISON: limit hwpoison injector to known page types
__memory_failure()'s workflow is

	set PG_hwpoison
	//...
	unset PG_hwpoison if didn't pass hwpoison filter

That could kill unrelated process if it happens to page fault on the
page with the (temporary) PG_hwpoison. The race should be big enough to
appear in stress tests.

Fix it by grabbing the page and checking filter at inject time.  This
also avoids the very noisy "Injecting memory failure..." messages.

- we don't touch madvise() based injection, because the filters are
  generally not necessary for it.
- if we want to apply the filters to h/w aided injection, we'd better to
  rearrange the logic in __memory_failure() instead of this patch.

AK: fix documentation, use drain all, cleanups

CC: Haicheng Li <haicheng.li@intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:59 +01:00
Wu Fengguang
7c116f2b0d HWPOISON: add fs/device filters
Filesystem data/metadata present the most tricky-to-isolate pages.
It requires careful code review and stress testing to get them right.

The fs/device filter helps to target the stress tests to some specific
filesystem pages. The filter condition is block device's major/minor
numbers:
        - corrupt-filter-dev-major
        - corrupt-filter-dev-minor
When specified (non -1), only page cache pages that belong to that
device will be poisoned.

The filters are checked reliably on the locked and refcounted page.

Haicheng: clear PG_hwpoison and drop bad page count if filter not OK
AK: Add documentation

CC: Haicheng Li <haicheng.li@intel.com>
CC: Nick Piggin <npiggin@suse.de>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:59 +01:00
Wu Fengguang
138ce286eb HWPOISON: return 0 to indicate success reliably
Return 0 to indicate success, when
- action result is RECOVERED or DELAYED
- no extra page reference

Note that dirty swapcache pages are kept in swapcache, so can have one
more reference count.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Wu Fengguang
d95ea51e3a HWPOISON: make semantics of IGNORED/DELAYED clear
Change semantics for
- IGNORED: not handled; it may well be _unsafe_
- DELAYED: to be handled later; it is _safe_

With this change,
- IGNORED/FAILED mean (maybe) Error
- DELAYED/RECOVERED mean Success

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Wu Fengguang
847ce401df HWPOISON: Add unpoisoning support
The unpoisoning interface is useful for stress testing tools to
reclaim poisoned pages (to prevent OOM)

There is no hardware level unpoisioning, so this
cannot be used for real memory errors, only for software injected errors.

Note that it may leak pages silently - those who have been removed from
LRU cache, but not isolated from page cache/swap cache at hwpoison time.
Especially the stress test of dirty swap cache pages shall reboot system
before exhausting memory.

AK: Fix comments, add documentation, add printks, rename symbol

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Wu Fengguang
8d22ba1b74 HWPOISON: detect free buddy pages explicitly
Most free pages in the buddy system have no PG_buddy set.
Introduce is_free_buddy_page() for detecting them reliably.

CC: Nick Piggin <npiggin@suse.de>
CC: Mel Gorman <mel@linux.vnet.ibm.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Wu Fengguang
95d01fc664 HWPOISON: remove the free buddy page handler
The buddy page has already be handled in the very beginning.
So remove redundant code.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Wu Fengguang
dc2a1cbf7d HWPOISON: introduce delete_from_lru_cache()
Introduce delete_from_lru_cache() to
- clear PG_active, PG_unevictable to avoid complains at unpoison time
- move the isolate_lru_page() call back to the handlers instead of the
  entrance of __memory_failure(), this is more hwpoison filter friendly

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Wu Fengguang
71f72525df HWPOISON: comment dirty swapcache pages
AK: Improve comment

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Wu Fengguang
db0480b3a6 HWPOISON: comment the possible set_page_dirty() race
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Wu Fengguang
1668bfd5be HWPOISON: abort on failed unmap
Don't try to isolate a still mapped page. Otherwise we will hit the
BUG_ON(page_mapped(page)) in __remove_from_page_cache().

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:58 +01:00
Andi Kleen
82ba011b90 HWPOISON: Turn ref argument into flags argument
Now that "ref" is just a boolean turn it into
a flags argument. First step is only a single flag
that makes the code's intention more clear, but more
may follow.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:57 +01:00
Wu Fengguang
bd1ce5f91f HWPOISON: avoid grabbing the page count multiple times during madvise injection
If page is double referenced in madvise_hwpoison() and __memory_failure(),
remove_mapping() will fail because it expects page_count=2. Fix it by
not grabbing extra page count in __memory_failure().

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:57 +01:00
Wu Fengguang
a7560fc80f HWPOISON: return ENXIO on invalid page number
Use a different errno than the usual EIO for invalid page numbers.
This is mainly for better reporting for the injector.

This also avoids calling action_result() with invalid pfn.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:57 +01:00
Wu Fengguang
9b9a29ecd7 HWPOISON: remove the anonymous entry
(PG_swapbacked && !PG_lru) pages should not happen.
Better to treat them as unknown pages.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:57 +01:00
Andi Kleen
588f9ce6ca HWPOISON: Be more aggressive at freeing non LRU caches
shake_page handles more types of page caches than lru_drain_all()

- per cpu page allocator pages
- per CPU LRU

Stops early when the page became free.

Used in followon patches.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:57 +01:00
Jie Zhang
ea63763959 nommu: fix malloc performance by adding uninitialized flag
The NOMMU code currently clears all anonymous mmapped memory.  While this
is what we want in the default case, all memory allocation from userspace
under NOMMU has to go through this interface, including malloc() which is
allowed to return uninitialized memory.  This can easily be a significant
performance penalty.  So for constrained embedded systems were security is
irrelevant, allow people to avoid clearing memory unnecessarily.

This also alters the ELF-FDPIC binfmt such that it obtains uninitialised
memory for the brk and stack region.

Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:24 -08:00
Naoya Horiguchi
5dc37642cb mm hugetlb: add hugepage support to pagemap
This patch enables extraction of the pfn of a hugepage from
/proc/pid/pagemap in an architecture independent manner.

Details
-------
My test program (leak_pagemap) works as follows:
 - creat() and mmap() a file on hugetlbfs (file size is 200MB == 100 hugepages,)
 - read()/write() something on it,
 - call page-types with option -p,
 - munmap() and unlink() the file on hugetlbfs

Without my patches
------------------
$ ./leak_pagemap
             flags page-count       MB  symbolic-flags                     long-symbolic-flags
0x0000000000000000          1        0  __________________________________
0x0000000000000804          1        0  __R________M______________________ referenced,mmap
0x000000000000086c         81        0  __RU_lA____M______________________ referenced,uptodate,lru,active,mmap
0x0000000000005808          5        0  ___U_______Ma_b___________________ uptodate,mmap,anonymous,swapbacked
0x0000000000005868         12        0  ___U_lA____Ma_b___________________ uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c          1        0  __RU_lA____Ma_b___________________ referenced,uptodate,lru,active,mmap,anonymous,swapbacked
             total        101        0

The output of page-types don't show any hugepage.

With my patches
---------------
$ ./leak_pagemap
             flags page-count       MB  symbolic-flags                     long-symbolic-flags
0x0000000000000000          1        0  __________________________________
0x0000000000030000      51100      199  ________________TG________________ compound_tail,huge
0x0000000000028018        100        0  ___UD__________H_G________________ uptodate,dirty,compound_head,huge
0x0000000000000804          1        0  __R________M______________________ referenced,mmap
0x000000000000080c          1        0  __RU_______M______________________ referenced,uptodate,mmap
0x000000000000086c         80        0  __RU_lA____M______________________ referenced,uptodate,lru,active,mmap
0x0000000000005808          4        0  ___U_______Ma_b___________________ uptodate,mmap,anonymous,swapbacked
0x0000000000005868         12        0  ___U_lA____Ma_b___________________ uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c          1        0  __RU_lA____Ma_b___________________ referenced,uptodate,lru,active,mmap,anonymous,swapbacked
             total      51300      200

The output of page-types shows 51200 pages contributing to hugepages,
containing 100 head pages and 51100 tail pages as expected.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:24 -08:00
Naoya Horiguchi
d33b9f45bd mm: hugetlb: fix hugepage memory leak in walk_page_range()
Most callers of pmd_none_or_clear_bad() check whether the target page is
in a hugepage or not, but walk_page_range() do not check it.  So if we
read /proc/pid/pagemap for the hugepage on x86 machine, the hugepage
memory is leaked as shown below.  This patch fixes it.

Details
=======
My test program (leak_pagemap) works as follows:
 - creat() and mmap() a file on hugetlbfs (file size is 200MB == 100 hugepages,)
 - read()/write() something on it,
 - call page-types with option -p (walk around the page tables),
 - munmap() and unlink() the file on hugetlbfs

Without my patches
------------------
$ cat /proc/meminfo |grep "HugePage"
HugePages_Total:    1000
HugePages_Free:     1000
HugePages_Rsvd:        0
HugePages_Surp:        0
$ ./leak_pagemap
[snip output]
$ cat /proc/meminfo |grep "HugePage"
HugePages_Total:    1000
HugePages_Free:      900
HugePages_Rsvd:        0
HugePages_Surp:        0
$ ls /hugetlbfs/
$

100 hugepages are accounted as used while there is no file on hugetlbfs.

With my patches
---------------
$ cat /proc/meminfo |grep "HugePage"
HugePages_Total:    1000
HugePages_Free:     1000
HugePages_Rsvd:        0
HugePages_Surp:        0
$ ./leak_pagemap
[snip output]
$ cat /proc/meminfo |grep "HugePage"
HugePages_Total:    1000
HugePages_Free:     1000
HugePages_Rsvd:        0
HugePages_Surp:        0
$ ls /hugetlbfs
$

No memory leaks.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:24 -08:00
Naoya Horiguchi
4f16fc107d mm: hugetlb: fix hugepage memory leak in mincore()
Most callers of pmd_none_or_clear_bad() check whether the target page is
in a hugepage or not, but mincore() and walk_page_range() do not check it.
 So if we use mincore() on a hugepage on x86 machine, the hugepage memory
is leaked as shown below.  This patch fixes it by extending mincore()
system call to support hugepages.

Details
=======
My test program (leak_mincore) works as follows:
 - creat() and mmap() a file on hugetlbfs (file size is 200MB == 100 hugepages,)
 - read()/write() something on it,
 - call mincore() for first ten pages and printf() the values of *vec
 - munmap() and unlink() the file on hugetlbfs

Without my patch
----------------
$ cat /proc/meminfo| grep "HugePage"
HugePages_Total:    1000
HugePages_Free:     1000
HugePages_Rsvd:        0
HugePages_Surp:        0
$ ./leak_mincore
vec[0] 0
vec[1] 0
vec[2] 0
vec[3] 0
vec[4] 0
vec[5] 0
vec[6] 0
vec[7] 0
vec[8] 0
vec[9] 0
$ cat /proc/meminfo |grep "HugePage"
HugePages_Total:    1000
HugePages_Free:      999
HugePages_Rsvd:        0
HugePages_Surp:        0
$ ls /hugetlbfs/
$

Return values in *vec from mincore() are set to 0, while the hugepage
should be in memory, and 1 hugepage is still accounted as used while
there is no file on hugetlbfs.

With my patch
-------------
$ cat /proc/meminfo| grep "HugePage"
HugePages_Total:    1000
HugePages_Free:     1000
HugePages_Rsvd:        0
HugePages_Surp:        0
$ ./leak_mincore
vec[0] 1
vec[1] 1
vec[2] 1
vec[3] 1
vec[4] 1
vec[5] 1
vec[6] 1
vec[7] 1
vec[8] 1
vec[9] 1
$ cat /proc/meminfo |grep "HugePage"
HugePages_Total:    1000
HugePages_Free:     1000
HugePages_Rsvd:        0
HugePages_Surp:        0
$ ls /hugetlbfs/
$

Return value in *vec set to 1 and no memory leaks.

[akpm@linux-foundation.org: cleanup]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:24 -08:00
Mel Gorman
536240f2bd hugetlb: abort a hugepage pool resize if a signal is pending
If a user asks for a hugepage pool resize but specified a large number,
the machine can begin trashing.  In response, they might hit ctrl-c but
signals are ignored and the pool resize continues until it fails an
allocation.  This can take a considerable amount of time so this patch
aborts a pool resize if a signal is pending.

Suggested by Dave Hansen.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:24 -08:00
Lee Schermerhorn
6927c1dd93 mlock: replace stale comments in munlock_vma_page()
Cleanup stale comments on munlock_vma_page().

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: 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>
2009-12-15 08:53:23 -08:00
Lee Schermerhorn
418b27ef50 mm: remove unevictable_migrate_page function
unevictable_migrate_page() in mm/internal.h is a relic of the since
removed UNEVICTABLE_LRU Kconfig option.  This patch removes the function
and open codes the test in migrate_page_copy().

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:23 -08:00