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* memcg: reduce check for softlimit excessKAMEZAWA Hiroyuki2009-10-01
| | | | | | | | | | | | | | | In charge/uncharge/reclaim path, usage_in_excess is calculated repeatedly and it takes res_counter's spin_lock every time. This patch removes unnecessary calls for res_count_soft_limit_excess. Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: some modification to softlimit under hierarchical memory reclaim.KAMEZAWA Hiroyuki2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch clean up/fixes for memcg's uncharge soft limit path. Problems: Now, res_counter_charge()/uncharge() handles softlimit information at charge/uncharge and softlimit-check is done when event counter per memcg goes over limit. Now, event counter per memcg is updated only when memory usage is over soft limit. Here, considering hierarchical memcg management, ancesotors should be taken care of. Now, ancerstors(hierarchy) are handled in charge() but not in uncharge(). This is not good. Prolems: 1. memcg's event counter incremented only when softlimit hits. That's bad. It makes event counter hard to be reused for other purpose. 2. At uncharge, only the lowest level rescounter is handled. This is bug. Because ancesotor's event counter is not incremented, children should take care of them. 3. res_counter_uncharge()'s 3rd argument is NULL in most case. ops under res_counter->lock should be small. No "if" sentense is better. Fixes: * Removed soft_limit_xx poitner and checks in charge and uncharge. Do-check-only-when-necessary scheme works enough well without them. * make event-counter of memcg incremented at every charge/uncharge. (per-cpu area will be accessed soon anyway) * All ancestors are checked at soft-limit-check. This is necessary because ancesotor's event counter may never be modified. Then, they should be checked at the same time. Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix refcnt going negativeKAMEZAWA Hiroyuki2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __mem_cgroup_largest_soft_limit_node() returns a mem_cgroup_per_zone "mz" with incremnted mz->mem->css's refcnt. Then, the caller of this function has to call css_put(mz->mem->css). But, mz can be !NULL even if "not found" i.e. without css_get(). By this, css->refcnt will go down to minus. This may cause various things...one of results will be initite-loop in css_tryget() as this. INFO: RCU detected CPU 0 stall (t=10000 jiffies) sending NMI to all CPUs: NMI backtrace for cpu 0 CPU 0: <snip> <<EOE>> <IRQ> [<ffffffff810884bd>] trace_hardirqs_off+0xd/0x10 [<ffffffff8102a940>] flat_send_IPI_mask+0x90/0xb0 [<ffffffff8102a9c9>] flat_send_IPI_all+0x69/0x70 [<ffffffff81027372>] arch_trigger_all_cpu_backtrace+0x62/0xa0 [<ffffffff810bff8e>] __rcu_pending+0x7e/0x370 [<ffffffff810c02c7>] rcu_check_callbacks+0x47/0x130 [<ffffffff81063a26>] update_process_times+0x46/0x70 [<ffffffff81085930>] tick_sched_timer+0x60/0x160 [<ffffffff810858d0>] ? tick_sched_timer+0x0/0x160 [<ffffffff8107a03a>] __run_hrtimer+0xba/0x150 [<ffffffff8107a325>] hrtimer_interrupt+0xd5/0x1b0 [<ffffffff81426dfe>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff8142cacd>] smp_apic_timer_interrupt+0x6d/0x9b [<ffffffff8100cb33>] apic_timer_interrupt+0x13/0x20 <EOI> [<ffffffff811317b6>] ? mem_cgroup_walk_tree+0x156/0x180 [<ffffffff811316d3>] ? mem_cgroup_walk_tree+0x73/0x180 [<ffffffff81131692>] ? mem_cgroup_walk_tree+0x32/0x180 [<ffffffff81131a00>] ? mem_cgroup_get_local_stat+0x0/0x110 [<ffffffff81131d5b>] ? mem_control_stat_show+0x14b/0x330 [<ffffffff810a57fd>] ? cgroup_seqfile_show+0x3d/0x60 Above shows CPU0 caught in css_tryget()'s inifinite loop because of bad refcnt. This is a fix to set mz=NULL at the top of retry path. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.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>
* memcg: show swap usage in stat fileDaisuke Nishimura2009-09-24
| | | | | | | | | | | | We now count MEM_CGROUP_STAT_SWAPOUT, so we can show swap usage. It would be useful for users to show swap usage in memory.stat file, because they don't need calculate memsw.usage - res.usage to know swap usage. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> 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>
* memcg: improve resource counter scalabilityBalbir Singh2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reduce the resource counter overhead (mostly spinlock) associated with the root cgroup. This is a part of the several patches to reduce mem cgroup overhead. I had posted other approaches earlier (including using percpu counters). Those patches will be a natural addition and will be added iteratively on top of these. The patch stops resource counter accounting for the root cgroup. The data for display is derived from the statisitcs we maintain via mem_cgroup_charge_statistics (which is more scalable). What happens today is that, we do double accounting, once using res_counter_charge() and once using memory_cgroup_charge_statistics(). For the root, since we don't implement limits any more, we don't need to track every charge via res_counter_charge() and check for limit being exceeded and reclaim. The main mem->res usage_in_bytes can be derived by summing the cache and rss usage data from memory statistics (MEM_CGROUP_STAT_RSS and MEM_CGROUP_STAT_CACHE). However, for memsw->res usage_in_bytes, we need additional data about swapped out memory. This patch adds a MEM_CGROUP_STAT_SWAPOUT and uses that along with MEM_CGROUP_STAT_RSS and MEM_CGROUP_STAT_CACHE to derive the memsw data. This data is computed recursively when hierarchy is enabled. The tests results I see on a 24 way show that 1. The lock contention disappears from /proc/lock_stats 2. The results of the test are comparable to running with cgroup_disable=memory. Here is a sample of my program runs Without Patch Performance counter stats for '/home/balbir/parallel_pagefault': 7192804.124144 task-clock-msecs # 23.937 CPUs 424691 context-switches # 0.000 M/sec 267 CPU-migrations # 0.000 M/sec 28498113 page-faults # 0.004 M/sec 5826093739340 cycles # 809.989 M/sec 408883496292 instructions # 0.070 IPC 7057079452 cache-references # 0.981 M/sec 3036086243 cache-misses # 0.422 M/sec 300.485365680 seconds time elapsed With cgroup_disable=memory Performance counter stats for '/home/balbir/parallel_pagefault': 7182183.546587 task-clock-msecs # 23.915 CPUs 425458 context-switches # 0.000 M/sec 203 CPU-migrations # 0.000 M/sec 92545093 page-faults # 0.013 M/sec 6034363609986 cycles # 840.185 M/sec 437204346785 instructions # 0.072 IPC 6636073192 cache-references # 0.924 M/sec 2358117732 cache-misses # 0.328 M/sec 300.320905827 seconds time elapsed With this patch applied Performance counter stats for '/home/balbir/parallel_pagefault': 7191619.223977 task-clock-msecs # 23.955 CPUs 422579 context-switches # 0.000 M/sec 88 CPU-migrations # 0.000 M/sec 91946060 page-faults # 0.013 M/sec 5957054385619 cycles # 828.333 M/sec 1058117350365 instructions # 0.178 IPC 9161776218 cache-references # 1.274 M/sec 1920494280 cache-misses # 0.267 M/sec 300.218764862 seconds time elapsed Data from Prarit (kernel compile with make -j64 on a 64 CPU/32G machine) For a single run Without patch real 27m8.988s user 87m24.916s sys 382m6.037s With patch real 4m18.607s user 84m58.943s sys 50m52.682s With config turned off real 4m54.972s user 90m13.456s sys 50m19.711s NOTE: The data looks counterintuitive due to the increased performance with the patch, even over the config being turned off. We probably need more runs, but so far all testing has shown that the patches definitely help. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> 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>
* memory controller: soft limit reclaim on contentionBalbir Singh2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement reclaim from groups over their soft limit Permit reclaim from memory cgroups on contention (via the direct reclaim path). memory cgroup soft limit reclaim finds the group that exceeds its soft limit by the largest number of pages and reclaims pages from it and then reinserts the cgroup into its correct place in the rbtree. Add additional checks to mem_cgroup_hierarchical_reclaim() to detect long loops in case all swap is turned off. The code has been refactored and the loop check (loop < 2) has been enhanced for soft limits. For soft limits, we try to do more targetted reclaim. Instead of bailing out after two loops, the routine now reclaims memory proportional to the size by which the soft limit is exceeded. The proportion has been empirically determined. [akpm@linux-foundation.org: build fix] [kamezawa.hiroyu@jp.fujitsu.com: fix softlimit css refcnt handling] [nishimura@mxp.nes.nec.co.jp: refcount of the "victim" should be decremented before exiting the loop] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
* memory controller: soft limit refactor reclaim flagsBalbir Singh2009-09-24
| | | | | | | | | | | | | | | Refactor mem_cgroup_hierarchical_reclaim() Refactor the arguments passed to mem_cgroup_hierarchical_reclaim() into flags, so that new parameters don't have to be passed as we make the reclaim routine more flexible Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> 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>
* memory controller: soft limit organize cgroupsBalbir Singh2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | Organize cgroups over soft limit in a RB-Tree Introduce an RB-Tree for storing memory cgroups that are over their soft limit. The overall goal is to 1. Add a memory cgroup to the RB-Tree when the soft limit is exceeded. We are careful about updates, updates take place only after a particular time interval has passed 2. We remove the node from the RB-Tree when the usage goes below the soft limit The next set of patches will exploit the RB-Tree to get the group that is over its soft limit by the largest amount and reclaim from it, when we face memory contention. [hugh.dickins@tiscali.co.uk: CONFIG_CGROUP_MEM_RES_CTLR=y CONFIG_PREEMPT=y fails to boot] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memory controller: soft limit interfaceBalbir Singh2009-09-24
| | | | | | | | | | | | | | | | | | | | | | Add an interface to allow get/set of soft limits. Soft limits for memory plus swap controller (memsw) is currently not supported. Resource counters have been enhanced to support soft limits and new type RES_SOFT_LIMIT has been added. Unlike hard limits, soft limits can be directly set and do not need any reclaim or checks before setting them to a newer value. Kamezawa-San raised a question as to whether soft limit should belong to res_counter. Since all resources understand the basic concepts of hard and soft limits, it is justified to add soft limits here. Soft limits are a generic resource usage feature, even file system quotas support soft limits. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> 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>
* memcg: add comments explaining memory barriersKAMEZAWA Hiroyuki2009-09-24
| | | | | | | | | | | Add comments for the reason of smp_wmb() in mem_cgroup_commit_charge(). [akpm@linux-foundation.org: coding-style fixes] Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> 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>
* memcg: remove the overhead associated with the root cgroupBalbir Singh2009-09-24
| | | | | | | | | | | | | | | | | | | | Change the memory cgroup to remove the overhead associated with accounting all pages in the root cgroup. As a side-effect, we can no longer set a memory hard limit in the root cgroup. A new flag to track whether the page has been accounted or not has been added as well. Flags are now set atomically for page_cgroup, pcg_default_flags is now obsolete and removed. [akpm@linux-foundation.org: fix a few documentation glitches] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroups: let ss->can_attach and ss->attach do whole threadgroups at a timeBen Blum2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | Alter the ss->can_attach and ss->attach functions to be able to deal with a whole threadgroup at a time, for use in cgroup_attach_proc. (This is a pre-patch to cgroup-procs-writable.patch.) Currently, new mode of the attach function can only tell the subsystem about the old cgroup of the threadgroup leader. No subsystem currently needs that information for each thread that's being moved, but if one were to be added (for example, one that counts tasks within a group) this bit would need to be reworked a bit to tell the subsystem the right information. [hidave.darkstar@gmail.com: fix build] Signed-off-by: Ben Blum <bblum@google.com> Signed-off-by: Paul Menage <menage@google.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Matt Helsley <matthltc@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: drop unneeded double negationsJohannes Weiner2009-09-22
| | | | | | | | | | Remove double negations where the operand is already boolean. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> 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>
* cgroup avoid permanent sleep at rmdirKAMEZAWA Hiroyuki2009-07-29
| | | | | | | | | | | | | | | | | | | | | After commit ec64f51545fffbc4cb968f0cea56341a4b07e85a ("cgroup: fix frequent -EBUSY at rmdir"), cgroup's rmdir (especially against memcg) doesn't return -EBUSY by temporary ref counts. That commit expects all refs after pre_destroy() is temporary but...it wasn't. Then, rmdir can wait permanently. This patch tries to fix that and change followings. - set CGRP_WAIT_ON_RMDIR flag before pre_destroy(). - clear CGRP_WAIT_ON_RMDIR flag when the subsys finds racy case. if there are sleeping ones, wakes them up. - rmdir() sleeps only when CGRP_WAIT_ON_RMDIR flag is set. Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Balbir Sigh <balbir@linux.vnet.ibm.com> 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>
* Fix congestion_wait() sync/async vs read/write confusionJens Axboe2009-07-10
| | | | | | | | Commit 1faa16d22877f4839bd433547d770c676d1d964c accidentally broke the bdi congestion wait queue logic, causing us to wait on congestion for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* memcg: fix lru rotation in isolate_pagesKAMEZAWA Hiroyuki2009-06-18
| | | | | | | | | | | | | | | | | | | Try to fix memcg's lru rotation sanity: make memcg use the same logic as the global LRU does. Now, at __isolate_lru_page() retruns -EBUSY, the page is rotated to the tail of LRU in global LRU's isolate LRU pages. But in memcg, it's not handled. This makes memcg do the same behavior as global LRU and rotate LRU in the page is busy. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> 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>
* memcg: fix behavior under memory.limit equals to memsw.limitKAMEZAWA Hiroyuki2009-06-18
| | | | | | | | | | | | | | | | | | | | | | | | A user can set memcg.limit_in_bytes == memcg.memsw.limit_in_bytes when the user just want to limit the total size of applications, in other words, not very interested in memory usage itself. In this case, swap-out will be done only by global-LRU. But, under current implementation, memory.limit_in_bytes is checked at first and try_to_free_page() may do swap-out. But, that swap-out is useless for memsw.limit_in_bytes and the thread may hit limit again. This patch tries to fix the current behavior at memory.limit == memsw.limit case. And documentation is updated to explain the behavior of this special case. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix swap accountingKAMEZAWA Hiroyuki2009-06-18
| | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes mis-accounting of swap usage in memcg. In the current implementation, memcg's swap account is uncharged only when swap is completely freed. But there are several cases where swap cannot be freed cleanly. For handling that, this patch changes that memcg uncharges swap account when swap has no references other than cache. By this, memcg's swap entry accounting can be fully synchronous with the application's behavior. This patch also changes memcg's hooks for swap-out. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Balbir Singh <balbir@in.ibm.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: remove some redundant checksLi Zefan2009-06-18
| | | | | | | | | | | We don't need to check do_swap_account in the case that the function which checks do_swap_account will never get called if do_swap_account == 0. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> 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>
* memcg: add file-based RSS accountingBalbir Singh2009-06-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add file RSS tracking per memory cgroup We currently don't track file RSS, the RSS we report is actually anon RSS. All the file mapped pages, come in through the page cache and get accounted there. This patch adds support for accounting file RSS pages. It should 1. Help improve the metrics reported by the memory resource controller 2. Will form the basis for a future shared memory accounting heuristic that has been proposed by Kamezawa. Unfortunately, we cannot rename the existing "rss" keyword used in memory.stat to "anon_rss". We however, add "mapped_file" data and hope to educate the end user through documentation. [hugh.dickins@tiscali.co.uk: fix mem_cgroup_update_mapped_file_stat oops] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.cn> Cc: Paul Menage <menage@google.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Signed-off-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>
* vmscan: evict use-once pages firstRik van Riel2009-06-16
| | | | | | | | | | | | | | | | | | | | | | | | | | When the file LRU lists are dominated by streaming IO pages, evict those pages first, before considering evicting other pages. This should be safe from deadlocks or performance problems because only three things can happen to an inactive file page: 1) referenced twice and promoted to the active list 2) evicted by the pageout code 3) under IO, after which it will get evicted or promoted The pages freed in this way can either be reused for streaming IO, or allocated for something else. If the pages are used for streaming IO, this pageout pattern continues. Otherwise, we will fall back to the normal pageout pattern. Signed-off-by: Rik van Riel <riel@redhat.com> Reported-by: Elladan <elladan@eskimo.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix build warning and avoid checking for mem != null again and againNikanth Karthikesan2009-05-29
| | | | | | | | | | | Fix build warning, "mem_cgroup_is_obsolete defined but not used" when CONFIG_DEBUG_VM is not set. Also avoid checking for !mem again and again. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> 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>
* memcg: fix deadlock between lock_page_cgroup and mapping tree_lockDaisuke Nishimura2009-05-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | mapping->tree_lock can be acquired from interrupt context. Then, following dead lock can occur. Assume "A" as a page. CPU0: lock_page_cgroup(A) interrupted -> take mapping->tree_lock. CPU1: take mapping->tree_lock -> lock_page_cgroup(A) This patch tries to fix above deadlock by moving memcg's hook to out of mapping->tree_lock. charge/uncharge of pagecache/swapcache is protected by page lock, not tree_lock. After this patch, lock_page_cgroup() is not called under mapping->tree_lock. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
* memcg: fix mem_cgroup_shrink_usage()Daisuke Nishimura2009-05-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Current mem_cgroup_shrink_usage() has two problems. 1. It doesn't call mem_cgroup_out_of_memory and doesn't update last_oom_jiffies, so pagefault_out_of_memory invokes global OOM. 2. Considering hierarchy, shrinking has to be done from the mem_over_limit, not from the memcg which the page would be charged to. mem_cgroup_try_charge_swapin() does all of these things properly, so we use it and call cancel_charge_swapin when it succeeded. The name of "shrink_usage" is not appropriate for this behavior, so we change it too. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.cn> Cc: Paul Menage <menage@google.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
* memcg: fix try_get_mem_cgroup_from_swapcache()Daisuke Nishimura2009-05-02
| | | | | | | | | | | | | | | | This is a bugfix for commit 3c776e64660028236313f0e54f3a9945764422df ("memcg: charge swapcache to proper memcg"). Used bit of swapcache is solid under page lock, but considering move_account, pc->mem_cgroup is not. We need lock_page_cgroup() anyway. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: remove warning when CONFIG_DEBUG_VM=nKAMEZAWA Hiroyuki2009-04-13
| | | | | | | | | | mm/memcontrol.c:318: warning: `mem_cgroup_is_obsolete' defined but not used [akpm@linux-foundation.org: simplify as suggested by Balbir] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> 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>
* memcg: cleanup cache_chargeDaisuke Nishimura2009-04-02
| | | | | | | | | | | | Current mem_cgroup_cache_charge is a bit complicated especially in the case of shmem's swap-in. This patch cleans it up by using try_charge_swapin and commit_charge_swapin. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
* cgroups: use css id in swap cgroup for saving memory v5KAMEZAWA Hiroyuki2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Try to use CSS ID for records in swap_cgroup. By this, on 64bit machine, size of swap_cgroup goes down to 2 bytes from 8bytes. This means, when 2GB of swap is equipped, (assume the page size is 4096bytes) From size of swap_cgroup = 2G/4k * 8 = 4Mbytes. To size of swap_cgroup = 2G/4k * 2 = 1Mbytes. Reduction is large. Of course, there are trade-offs. This CSS ID will add overhead to swap-in/swap-out/swap-free. But in general, - swap is a resource which the user tend to avoid use. - If swap is never used, swap_cgroup area is not used. - Reading traditional manuals, size of swap should be proportional to size of memory. Memory size of machine is increasing now. I think reducing size of swap_cgroup makes sense. Note: - ID->CSS lookup routine has no locks, it's under RCU-Read-Side. - memcg can be obsolete at rmdir() but not freed while refcnt from swap_cgroup is available. Changelog v4->v5: - reworked on to memcg-charge-swapcache-to-proper-memcg.patch Changlog ->v4: - fixed not configured case. - deleted unnecessary comments. - fixed NULL pointer bug. - fixed message in dmesg. [nishimura@mxp.nes.nec.co.jp: css_tryget can be called twice in !PageCgroupUsed case] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Hugh Dickins <hugh@veritas.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>
* memcg: charge swapcache to proper memcgDaisuke Nishimura2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | memcg_test.txt says at 4.1: This swap-in is one of the most complicated work. In do_swap_page(), following events occur when pte is unchanged. (1) the page (SwapCache) is looked up. (2) lock_page() (3) try_charge_swapin() (4) reuse_swap_page() (may call delete_swap_cache()) (5) commit_charge_swapin() (6) swap_free(). Considering following situation for example. (A) The page has not been charged before (2) and reuse_swap_page() doesn't call delete_from_swap_cache(). (B) The page has not been charged before (2) and reuse_swap_page() calls delete_from_swap_cache(). (C) The page has been charged before (2) and reuse_swap_page() doesn't call delete_from_swap_cache(). (D) The page has been charged before (2) and reuse_swap_page() calls delete_from_swap_cache(). memory.usage/memsw.usage changes to this page/swp_entry will be Case (A) (B) (C) (D) Event Before (2) 0/ 1 0/ 1 1/ 1 1/ 1 =========================================== (3) +1/+1 +1/+1 +1/+1 +1/+1 (4) - 0/ 0 - -1/ 0 (5) 0/-1 0/ 0 -1/-1 0/ 0 (6) - 0/-1 - 0/-1 =========================================== Result 1/ 1 1/ 1 1/ 1 1/ 1 In any cases, charges to this page should be 1/ 1. In case of (D), mem_cgroup_try_get_from_swapcache() returns NULL (because lookup_swap_cgroup() returns NULL), so "+1/+1" at (3) means charges to the memcg("foo") to which the "current" belongs. OTOH, "-1/0" at (4) and "0/-1" at (6) means uncharges from the memcg("baa") to which the page has been charged. So, if the "foo" and "baa" is different(for example because of task move), this charge will be moved from "baa" to "foo". I think this is an unexpected behavior. This patch fixes this by modifying mem_cgroup_try_get_from_swapcache() to return the memcg to which the swapcache has been charged if PCG_USED bit is set. IIUC, checking PCG_USED bit of swapcache is safe under page lock. Signed-off-by: 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: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: remove mem_cgroup_calc_mapped_ratio()KOSAKI Motohiro2009-04-02
| | | | | | | | | | | | Currently, mem_cgroup_calc_mapped_ratio() is unused at all. it can be removed and KAMEZAWA-san suggested it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.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>
* memcg: show memcg information during OOMBalbir Singh2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add RSS and swap to OOM output from memcg Display memcg values like failcnt, usage and limit when an OOM occurs due to memcg. Thanks to Johannes Weiner, Li Zefan, David Rientjes, Kamezawa Hiroyuki, Daisuke Nishimura and KOSAKI Motohiro for review. Sample output ------------- Task in /a/x killed as a result of limit of /a memory: usage 1048576kB, limit 1048576kB, failcnt 4183 memory+swap: usage 1400964kB, limit 9007199254740991kB, failcnt 0 [akpm@linux-foundation.org: compilation fix] [akpm@linux-foundation.org: fix kerneldoc and whitespace] [akpm@linux-foundation.org: add printk facility level] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.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>
* memcg: fix OOM killer under memcgKAMEZAWA Hiroyuki2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch tries to fix OOM Killer problems caused by hierarchy. Now, memcg itself has OOM KILL function (in oom_kill.c) and tries to kill a task in memcg. But, when hierarchy is used, it's broken and correct task cannot be killed. For example, in following cgroup /groupA/ hierarchy=1, limit=1G, 01 nolimit 02 nolimit All tasks' memory usage under /groupA, /groupA/01, groupA/02 is limited to groupA's 1Gbytes but OOM Killer just kills tasks in groupA. This patch provides makes the bad process be selected from all tasks under hierarchy. BTW, currently, oom_jiffies is updated against groupA in above case. oom_jiffies of tree should be updated. To see how oom_jiffies is used, please check mem_cgroup_oom_called() callers. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: const fix] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix shrinking memory to return -EBUSY by fixing retry algorithmKAMEZAWA Hiroyuki2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As pointed out, shrinking memcg's limit should return -EBUSY after reasonable retries. This patch tries to fix the current behavior of shrink_usage. Before looking into "shrink should return -EBUSY" problem, we should fix hierarchical reclaim code. It compares current usage and current limit, but it only makes sense when the kernel reclaims memory because hit limits. This is also a problem. What this patch does are. 1. add new argument "shrink" to hierarchical reclaim. If "shrink==true", hierarchical reclaim returns immediately and the caller checks the kernel should shrink more or not. (At shrinking memory, usage is always smaller than limit. So check for usage < limit is useless.) 2. For adjusting to above change, 2 changes in "shrink"'s retry path. 2-a. retry_count depends on # of children because the kernel visits the children under hierarchy one by one. 2-b. rather than checking return value of hierarchical_reclaim's progress, compares usage-before-shrink and usage-after-shrink. If usage-before-shrink <= usage-after-shrink, retry_count is decremented. Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: hierarchical statKAMEZAWA Hiroyuki2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up memory.stat file routine and show "total" hierarchical stat. This patch does - renamed get_all_zonestat to be get_local_zonestat. - remove old mem_cgroup_stat_desc, which is only for per-cpu stat. - add mcs_stat to cover both of per-cpu/per-lru stat. - add "total" stat of hierarchy (*) - add a callback system to scan all memcg under a root. == "total" is added. [kamezawa@localhost ~]$ cat /opt/cgroup/xxx/memory.stat cache 0 rss 0 pgpgin 0 pgpgout 0 inactive_anon 0 active_anon 0 inactive_file 0 active_file 0 unevictable 0 hierarchical_memory_limit 50331648 hierarchical_memsw_limit 9223372036854775807 total_cache 65536 total_rss 192512 total_pgpgin 218 total_pgpgout 155 total_inactive_anon 0 total_active_anon 135168 total_inactive_file 61440 total_active_file 4096 total_unevictable 0 == (*) maybe the user can do calc hierarchical stat by his own program in userland but if it can be written in clean way, it's worth to be shown, I think. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: use CSS IDKAMEZAWA Hiroyuki2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Assigning CSS ID for each memcg and use css_get_next() for scanning hierarchy. Assume folloing tree. group_A (ID=3) /01 (ID=4) /0A (ID=7) /02 (ID=10) group_B (ID=5) and task in group_A/01/0A hits limit at group_A. reclaim will be done in following order (round-robin). group_A(3) -> group_A/01 (4) -> group_A/01/0A (7) -> group_A/02(10) -> group_A -> ..... Round robin by ID. The last visited cgroup is recorded and restart from it when it start reclaim again. (More smart algorithm can be implemented..) No cgroup_mutex or hierarchy_mutex is required. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: fix frequent -EBUSY at rmdirKAMEZAWA Hiroyuki2009-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In following situation, with memory subsystem, /groupA use_hierarchy==1 /01 some tasks /02 some tasks /03 some tasks /04 empty When tasks under 01/02/03 hit limit on /groupA, hierarchical reclaim is triggered and the kernel walks tree under groupA. In this case, rmdir /groupA/04 fails with -EBUSY frequently because of temporal refcnt from the kernel. In general. cgroup can be rmdir'd if there are no children groups and no tasks. Frequent fails of rmdir() is not useful to users. (And the reason for -EBUSY is unknown to users.....in most cases) This patch tries to modify above behavior, by - retries if css_refcnt is got by someone. - add "return value" to pre_destroy() and allows subsystem to say "we're really busy!" Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.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>
* memcg: NULL pointer dereference at rmdir on some NUMA systemsKAMEZAWA Hiroyuki2009-01-29
| | | | | | | | | | | | | | | N_POSSIBLE doesn't means there is memory...and force_empty can visit invalid node which have no pgdat. To visit all valid nodes, N_HIGH_MEMORY should be used. Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.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>
* memcg: get/put parents at create/freeDaisuke Nishimura2009-01-29
| | | | | | | | | | | | | | | | | | | | | | The lifetime of struct cgroup and struct mem_cgroup is different and mem_cgroup has its own reference count for handling references from swap_cgroup. This causes strange problem that the parent mem_cgroup dies while child mem_cgroup alive, and this problem causes a bug in case of use_hierarchy==1 because res_counter_uncharge climbs up the tree. This patch is for avoiding it by getting the parent at create, and putting it at freeing. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by; KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix a race when setting memory.swappinessLi Zefan2009-01-15
| | | | | | | | | | | | | | | | | | | | | | | | (suppose: memcg->use_hierarchy == 0 and memcg->swappiness == 60) echo 10 > /memcg/0/swappiness | mem_cgroup_swappiness_write() | ... | echo 1 > /memcg/0/use_hierarchy | mkdir /mnt/0/1 | sub_memcg->swappiness = 60; memcg->swappiness = 10; | In the above scenario, we end up having 2 different swappiness values in a single hierarchy. We should hold cgroup_lock() when cheking cgrp->children list. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@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>
* memcg: fix section mismatchLi Zefan2009-01-15
| | | | | | | | | | | | | At system boot when creating the top cgroup, mem_cgroup_create() calls enable_swap_cgroup() which is marked as __init, so mark mem_cgroup_create() as __ref to avoid false section mismatch warning. Reported-by: Rakib Mullick <rakib.mullick@gmail.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> 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>
* memcg: make oom less frequentlyDaisuke Nishimura2009-01-15
| | | | | | | | | | | | | | | | | | | | In previous implementation, mem_cgroup_try_charge checked the return value of mem_cgroup_try_to_free_pages, and just retried if some pages had been reclaimed. But now, try_charge(and mem_cgroup_hierarchical_reclaim called from it) only checks whether the usage is less than the limit. This patch tries to change the behavior as before to cause oom less frequently. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix hierarchical reclaimDaisuke Nishimura2009-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | | If root_mem has no children, last_scaned_child is set to root_mem itself. But after some children added to root_mem, mem_cgroup_get_next_node can mem_cgroup_put the root_mem although root_mem has not been mem_cgroup_get. This patch fixes this behavior by: - Set last_scanned_child to NULL if root_mem has no children or DFS search has returned to root_mem itself(root_mem is not a "child" of root_mem). Make mem_cgroup_get_first_node return root_mem in this case. There are no mem_cgroup_get/put for root_mem. - Rename mem_cgroup_get_next_node to __mem_cgroup_get_next_node, and mem_cgroup_get_first_node to mem_cgroup_get_next_node. Make mem_cgroup_hierarchical_reclaim call only new mem_cgroup_get_next_node. Signed-off-by: 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: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix error path of mem_cgroup_move_parentDaisuke Nishimura2009-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | There is a bug in error path of mem_cgroup_move_parent. Extra refcnt got from try_charge should be dropped, and usages incremented by try_charge should be decremented in both error paths: A: failure at get_page_unless_zero B: failure at isolate_lru_page This bug makes this parent directory unremovable. In case of A, rmdir doesn't return, because res.usage doesn't go down to 0 at mem_cgroup_force_empty even after all the pc in lru are removed. In case of B, rmdir fails and returns -EBUSY, because it has extra ref counts even after res.usage goes down to 0. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix mem_cgroup_get_reclaim_stat_from_pageDaisuke Nishimura2009-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case of swapin, a new page is added to lru before it is charged, so page->pc->mem_cgroup points to NULL or last mem_cgroup the page was charged before. In the latter case, if the mem_cgroup has already freed by rmdir, the area pointed to by page->pc->mem_cgroup may have invalid data. Actually, I saw general protection fault. general protection fault: 0000 [#1] SMP last sysfs file: /sys/devices/system/cpu/cpu15/cache/index1/shared_cpu_map CPU 4 Modules linked in: ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp ipv6 autofs4 hidp rfcomm l2cap bluetooth sunrpc dm_mirror dm_region_hash dm_log dm_multipath dm_mod rfkill input_polldev sbs sbshc battery ac lp sg ide_cd_mod cdrom button serio_raw acpi_memhotplug parport_pc e1000 rtc_cmos parport rtc_core rtc_lib i2c_i801 i2c_core shpchp pcspkr ata_piix libata megaraid_mbox megaraid_mm sd_mod scsi_mod ext3 jbd ehci_hcd ohci_hcd uhci_hcd [last unloaded: microcode] Pid: 26038, comm: page01 Tainted: G W 2.6.28-rc9-mm1-mmotm-2008-12-22-16-14-f2ab3dea #1 RIP: 0010:[<ffffffff8028e710>] [<ffffffff8028e710>] update_page_reclaim_stat+0x2f/0x42 RSP: 0000:ffff8801ee457da8 EFLAGS: 00010002 RAX: 32353438312021c8 RBX: 0000000000000000 RCX: 32353438312021c8 RDX: 0000000000000000 RSI: ffff8800cb0b1000 RDI: ffff8801164d1d28 RBP: ffff880110002cb8 R08: ffff88010f2eae23 R09: 0000000000000001 R10: ffff8800bc514b00 R11: ffff880110002c00 R12: 0000000000000000 R13: ffff88000f484100 R14: 0000000000000003 R15: 00000000001200d2 FS: 00007f8a261726f0(0000) GS:ffff88010f2eaa80(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f8a25d22000 CR3: 00000001ef18c000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process page01 (pid: 26038, threadinfo ffff8801ee456000, task ffff8800b585b960) Stack: ffffe200071ee568 ffff880110001f00 0000000000000000 ffffffff8028ea17 ffff88000f484100 0000000000000000 0000000000000020 00007f8a25d22000 ffff8800bc514b00 ffffffff8028ec34 0000000000000000 0000000000016fd8 Call Trace: [<ffffffff8028ea17>] ? ____pagevec_lru_add+0xc1/0x13c [<ffffffff8028ec34>] ? drain_cpu_pagevecs+0x36/0x89 [<ffffffff802a4f8c>] ? swapin_readahead+0x78/0x98 [<ffffffff8029a37a>] ? handle_mm_fault+0x3d9/0x741 [<ffffffff804da654>] ? do_page_fault+0x3ce/0x78c [<ffffffff804d7a42>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff804d860f>] ? page_fault+0x1f/0x30 Code: cc 55 48 8d af b8 0d 00 00 48 89 f7 53 89 d3 e8 39 85 02 00 48 63 d3 48 ff 44 d5 10 45 85 e4 74 05 48 ff 44 d5 00 48 85 c0 74 0e <48> ff 44 d0 10 45 85 e4 74 04 48 ff 04 d0 5b 5d 41 5c c3 41 54 RIP [<ffffffff8028e710>] update_page_reclaim_stat+0x2f/0x42 RSP <ffff8801ee457da8> 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> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroups: use hierarchy_mutex in memory controllerPaul Menage2009-01-08
| | | | | | | | | | | | | Update the memory controller to use its hierarchy_mutex rather than calling cgroup_lock() to protected against cgroup_mkdir()/cgroup_rmdir() from occurring in its hierarchy. Signed-off-by: Paul Menage <menage@google.com> Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix shmem's swap accountingKAMEZAWA Hiroyuki2009-01-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now, you can see following even when swap accounting is enabled. 1. Create Group 01, and 02. 2. allocate a "file" on tmpfs by a task under 01. 3. swap out the "file" (by memory pressure) 4. Read "file" from a task in group 02. 5. the charge of "file" is moved to group 02. This is not ideal behavior. This is because SwapCache which was loaded by read-ahead is not taken into account.. This is a patch to fix shmem's swapcache behavior. - remove mem_cgroup_cache_charge_swapin(). - Add SwapCache handler routine to mem_cgroup_cache_charge(). By this, shmem's file cache is charged at add_to_page_cache() with GFP_NOWAIT. - pass the page of swapcache to shrink_mem_cgroup. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: fix LRU accounting for SwapCacheKAMEZAWA Hiroyuki2009-01-08
| | | | | | | | | | | | | | | | | | | | Now, a page can be deleted from SwapCache while do_swap_page(). memcg-fix-swap-accounting-leak-v3.patch handles that, but, LRU handling is still broken. (above behavior broke assumption of memcg-synchronized-lru patch.) This patch is a fix for LRU handling (especially for per-zone counters). At charging SwapCache, - Remove page_cgroup from LRU if it's not used. - Add page cgroup to LRU if it's not linked to. Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> 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>
* memcg: use css_tryget in memcgKAMEZAWA Hiroyuki2009-01-08
| | | | | | | | | | | | | | | | | | | | From:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> css_tryget() newly is added and we can know css is alive or not and get refcnt of css in very safe way. ("alive" here means "rmdir/destroy" is not called.) This patch replaces css_get() to css_tryget(), where I cannot explain why css_get() is safe. And removes memcg->obsolete flag. Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
* memcg: fix double free and make refcnt saneKAMEZAWA Hiroyuki2009-01-08
| | | | | | | | | | | | | | | | 1. Fix double-free BUG in error route of mem_cgroup_create(). mem_cgroup_free() itself frees per-zone-info. 2. Making refcnt of memcg simple. Add 1 refcnt at creation and call free when refcnt goes down to 0. Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
* memcg: fix swap accounting leakKAMEZAWA Hiroyuki2009-01-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix swapin charge operation of memcg. Now, memcg has hooks to swap-out operation and checks SwapCache is really unused or not. That check depends on contents of struct page. I.e. If PageAnon(page) && page_mapped(page), the page is recoginized as still-in-use. Now, reuse_swap_page() calles delete_from_swap_cache() before establishment of any rmap. Then, in followinig sequence (Page fault with WRITE) try_charge() (charge += PAGESIZE) commit_charge() (Check page_cgroup is used or not..) reuse_swap_page() -> delete_from_swapcache() -> mem_cgroup_uncharge_swapcache() (charge -= PAGESIZE) ...... New charge is uncharged soon.... To avoid this, move commit_charge() after page_mapcount() goes up to 1. By this, try_charge() (usage += PAGESIZE) reuse_swap_page() (may usage -= PAGESIZE if PCG_USED is set) commit_charge() (If page_cgroup is not marked as PCG_USED, add new charge.) Accounting will be correct. Changelog (v2) -> (v3) - fixed invalid charge to swp_entry==0. - updated documentation. Changelog (v1) -> (v2) - fixed comment. [nishimura@mxp.nes.nec.co.jp: swap accounting leak doc fix] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
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