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2009-12-16memcg: code clean, remove unused variable in mem_cgroup_resize_limit()Bob Liu
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>
2009-12-16memcg: remove memcg_tasklistDaisuke Nishimura
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>
2009-12-16memcg: avoid oom-killing innocent task in case of use_hierarchyDaisuke Nishimura
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>
2009-12-16memcg: cleanup mem_cgroup_move_parent()Daisuke Nishimura
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>
2009-12-16memcg: add mem_cgroup_cancel_charge()Daisuke Nishimura
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>
2009-12-16memcg: make memcg's file mapped consistent with global VMKAMEZAWA Hiroyuki
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>
2009-12-16memcg: coalesce charging via percpu storageKAMEZAWA Hiroyuki
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>
2009-12-16memcg: coalesce uncharge during unmap/truncateKAMEZAWA Hiroyuki
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>
2009-12-16memcg: fix memory.memsw.usage_in_bytes for root cgroupKirill A. Shutemov
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>
2009-12-16oom-kill: fix NUMA constraint check with nodemaskKAMEZAWA Hiroyuki
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>
2009-12-16oom-kill: show virtual size and rss information of the killed processKOSAKI Motohiro
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>
2009-12-16HWPOISON: Remove stray phrase in a commentAndi Kleen
Better to have complete sentences. Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: Try to allocate migration page on the same nodeAndi Kleen
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: Don't do early filtering if filter is disabledAndi Kleen
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: Add a madvise() injector for soft page offliningAndi Kleen
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>
2009-12-16HWPOISON: Add soft page offline supportAndi Kleen
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>
2009-12-16HWPOISON: Undefine short-hand macros after use to avoid namespace conflictAndi Kleen
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: Use new shake_page in memory_failureAndi Kleen
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>
2009-12-16HWPOISON: mention HWPoison in Kconfig entryAndi Kleen
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: Use get_user_page_fast in hwpoison madviseAndi Kleen
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>
2009-12-16HWPOISON: add an interface to switch off/on all the page filtersHaicheng Li
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>
2009-12-16HWPOISON: add memory cgroup filterAndi Kleen
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>
2009-12-16memcg: add accessor to mem_cgroup.cssWu Fengguang
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>
2009-12-16memcg: rename and export try_get_mem_cgroup_from_page()Wu Fengguang
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>
2009-12-16HWPOISON: add page flags filterWu Fengguang
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>
2009-12-16HWPOISON: limit hwpoison injector to known page typesWu Fengguang
__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>
2009-12-16HWPOISON: add fs/device filtersWu Fengguang
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>
2009-12-16HWPOISON: return 0 to indicate success reliablyWu Fengguang
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>
2009-12-16HWPOISON: make semantics of IGNORED/DELAYED clearWu Fengguang
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>
2009-12-16HWPOISON: Add unpoisoning supportWu Fengguang
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>
2009-12-16HWPOISON: detect free buddy pages explicitlyWu Fengguang
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>
2009-12-16HWPOISON: remove the free buddy page handlerWu Fengguang
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>
2009-12-16HWPOISON: introduce delete_from_lru_cache()Wu Fengguang
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>
2009-12-16HWPOISON: comment dirty swapcache pagesWu Fengguang
AK: Improve comment Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: comment the possible set_page_dirty() raceWu Fengguang
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16HWPOISON: abort on failed unmapWu Fengguang
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>
2009-12-16HWPOISON: Turn ref argument into flags argumentAndi Kleen
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>
2009-12-16HWPOISON: avoid grabbing the page count multiple times during madvise injectionWu Fengguang
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>
2009-12-16HWPOISON: return ENXIO on invalid page numberWu Fengguang
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>
2009-12-16HWPOISON: remove the anonymous entryWu Fengguang
(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>
2009-12-16HWPOISON: Be more aggressive at freeing non LRU cachesAndi Kleen
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>
2009-12-15nommu: fix malloc performance by adding uninitialized flagJie Zhang
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>
2009-12-15mm hugetlb: add hugepage support to pagemapNaoya Horiguchi
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>
2009-12-15mm: hugetlb: fix hugepage memory leak in walk_page_range()Naoya Horiguchi
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>
2009-12-15mm: hugetlb: fix hugepage memory leak in mincore()Naoya Horiguchi
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>
2009-12-15hugetlb: abort a hugepage pool resize if a signal is pendingMel Gorman
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>
2009-12-15mlock: replace stale comments in munlock_vma_page()Lee Schermerhorn
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>
2009-12-15mm: remove unevictable_migrate_page functionLee Schermerhorn
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>
2009-12-15hugetlb: acquire the i_mmap_lock before walking the prio_tree to unmap a pageMel Gorman
When the owner of a mapping fails COW because a child process is holding a reference, the children VMAs are walked and the page is unmapped. The i_mmap_lock is taken for the unmapping of the page but not the walking of the prio_tree. In theory, that tree could be changing if the lock is not held. This patch takes the i_mmap_lock properly for the duration of the prio_tree walk. [hugh.dickins@tiscali.co.uk: Spotted the problem in the first place] Signed-off-by: Mel Gorman <mel@csn.ul.ie> 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>
2009-12-15mm: uncached vma support with writenotifyMagnus Damm
Modify the generic mmap() code to keep the cache attribute in vma->vm_page_prot regardless if writenotify is enabled or not. Without this patch the cache configuration selected by f_op->mmap() is overwritten if writenotify is enabled, making it impossible to keep the vma uncached. Needed by drivers such as drivers/video/sh_mobile_lcdcfb.c which uses deferred io together with uncached memory. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jaya Kumar <jayakumar.lkml@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>