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* memcg: update documentationKAMEZAWA Hiroyuki2010-05-271-93/+198
| | | | | | | | | | | | Some information are old, and I think current document doesn't work as "a guide for users". We need summary of all of our controls, at least. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Randy Dunlap <randy.dunlap@oracle.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: move charge of file pagesDaisuke Nishimura2010-05-271-6/+12
| | | | | | | | | | | | | | | | | | | | | | This patch adds support for moving charge of file pages, which include normal file, tmpfs file and swaps of tmpfs file. It's enabled by setting bit 1 of <target cgroup>/memory.move_charge_at_immigrate. Unlike the case of anonymous pages, file pages(and swaps) in the range mmapped by the task will be moved even if the task hasn't done page fault, i.e. they might not be the task's "RSS", but other task's "RSS" that maps the same file. And mapcount of the page is ignored(the page can be moved even if page_mapcount(page) > 1). So, conditions that the page/swap should be met to be moved is that it must be in the range mmapped by the target task and it must be charged to the old cgroup. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix warning] 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: oom kill disable and oom statusKAMEZAWA Hiroyuki2010-05-271-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a feature to disable oom-killer for memcg, if disabled, of course, tasks under memcg will stop. But now, we have oom-notifier for memcg. And the world around memcg is not under out-of-memory. memcg's out-of-memory just shows memcg hits limit. Then, administrator or management daemon can recover the situation by - kill some process - enlarge limit, add more swap. - migrate some tasks - remove file cache on tmps (difficult ?) Unlike oom-killer, you can take enough information before killing tasks. (by gcore, or, ps etc.) [akpm@linux-foundation.org: coding-style fixes] 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: 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: oom notifierKAMEZAWA Hiroyuki2010-05-271-1/+19
| | | | | | | | | | | | | | | | | | | | | | | Considering containers or other resource management softwares in userland, event notification of OOM in memcg should be implemented. Now, memcg has "threshold" notifier which uses eventfd, we can make use of it for oom notification. This patch adds oom notification eventfd callback for memcg. The usage is very similar to threshold notifier, but control file is memory.oom_control and no arguments other than eventfd is required. % cgroup_event_notifier /cgroup/A/memory.oom_control dummy (About cgroup_event_notifier, see Documentation/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: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation/: it's -> its where appropriateFrancis Galiegue2010-04-231-1/+1
| | | | | | | | Fix obvious cases of "it's" being used when "its" was meant. Signed-off-by: Francis Galiegue <fgaliegue@gmail.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* memcg: fix typo in memcg documentationGreg Thelen2010-03-191-1/+1
| | | | | | | | Updated memory.txt to be more consistent: s/swapiness/swappiness/ Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* memcg: handle panic_on_oom=always caseKAMEZAWA Hiroyuki2010-03-131-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Presently, if panic_on_oom=2, the whole system panics even if the oom happend in some special situation (as cpuset, mempolicy....). Then, panic_on_oom=2 means painc_on_oom_always. Now, memcg doesn't check panic_on_oom flag. This patch adds a check. BTW, how it's useful ? kdump+panic_on_oom=2 is the last tool to investigate what happens in oom-ed system. When a task is killed, the sysytem recovers and there will be few hint to know what happnes. In mission critical system, oom should never happen. Then, panic_on_oom=2+kdump is useful to avoid next OOM by knowing precise information via snapshot. TODO: - For memcg, it's for isolate system's memory usage, oom-notiifer and freeze_at_oom (or rest_at_oom) should be implemented. Then, management daemon can do similar jobs (as kdump) or taking snapshot per cgroup. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Reviewed-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: implement memory thresholdsKirill A. Shutemov2010-03-131-1/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It allows to register multiple memory and memsw thresholds and gets notifications when it crosses. To register a threshold application need: - create an eventfd; - open memory.usage_in_bytes or memory.memsw.usage_in_bytes; - write string like "<event_fd> <memory.usage_in_bytes> <threshold>" to cgroup.event_control. Application will be notified through eventfd when memory usage crosses threshold in any direction. It's applicable for root and non-root cgroup. It uses stats to track memory usage, simmilar to soft limits. It checks if we need to send event to userspace on every 100 page in/out. I guess it's good compromise between performance and accuracy of thresholds. [akpm@linux-foundation.org: coding-style fixes] [nishimura@mxp.nes.nec.co.jp: fix documentation merge issue] Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Dan Malek <dan@embeddedalley.com> Cc: Vladislav Buzov <vbuzov@embeddedalley.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Alexander Shishkin <virtuoso@slind.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memcg: move charges of anonymous swapDaisuke Nishimura2010-03-131-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is another core part of this move-charge-at-task-migration feature. It enables moving charges of anonymous swaps. To move the charge of swap, we need to exchange swap_cgroup's record. In current implementation, swap_cgroup's record is protected by: - page lock: if the entry is on swap cache. - swap_lock: if the entry is not on swap cache. This works well in usual swap-in/out activity. But this behavior make the feature of moving swap charge check many conditions to exchange swap_cgroup's record safely. So I changed modification of swap_cgroup's recored(swap_cgroup_record()) to use xchg, and define a new function to cmpxchg swap_cgroup's record. This patch also enables moving charge of non pte_present but not uncharged swap caches, which can be exist on swap-out path, by getting the target pages via find_get_page() as do_mincore() does. [kosaki.motohiro@jp.fujitsu.com: fix ia64 build] [akpm@linux-foundation.org: fix typos] 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> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-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>
* memcg: add interface to move charge at task migrationDaisuke Nishimura2010-03-131-2/+54
| | | | | | | | | | | | | | | | | | | | | | | | | In current memcg, charges associated with a task aren't moved to the new cgroup at task migration. Some users feel this behavior to be strange. These patches are for this feature, that is, for charging to the new cgroup and, of course, uncharging from the old cgroup at task migration. This patch adds "memory.move_charge_at_immigrate" file, which is a flag file to determine whether charges should be moved to the new cgroup at task migration or not and what type of charges should be moved. This patch also adds read and write handlers of the file. This patch also adds no-op handlers for this feature. These handlers will be implemented in later patches. And you cannot write any values other than 0 to move_charge_at_immigrate yet. 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> Cc: Li Zefan <lizf@cn.fujitsu.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>
* memory controller: soft limit documentationBalbir Singh2009-09-241-1/+36
| | | | | | | | | | | | | | | | | | | | | | | | | Soft limits is a new feature for the memory resource controller, something similar has existed in the group scheduler in the form of shares. The CPU controllers interpretation of shares is very different though. Soft limits are the most useful feature to have for environments where the administrator wants to overcommit the system, such that only on memory contention do the limits become active. The current soft limits implementation provides a soft_limit_in_bytes interface for the memory controller and not for memory+swap controller. The implementation maintains an RB-Tree of groups that exceed their soft limit and starts reclaiming from the group that exceeds this limit by the maximum amount. This patch: Add documentation for 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: remove the overhead associated with the root cgroupBalbir Singh2009-09-241-0/+4
| | | | | | | | | | | | | | | | | | | | 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>
* memcg: add interface to reset limitsDaisuke Nishimura2009-06-181-0/+1
| | | | | | | | | | | | | | | | We don't have an interface to reset mem.limit or memsw.limit now. This patch allows to reset mem.limit or memsw.limit when they are being set to -1. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> 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 behavior under memory.limit equals to memsw.limitKAMEZAWA Hiroyuki2009-06-181-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | 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 documentationBharata B Rao2009-04-141-23/+32
| | | | | | | | | | | | | The description about various statistics from memory.stat is not accurate and confusing at times. Correct this along with a few other minor cleanups. Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Acked-by: 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>
* trivial: cgroups: documentation typo and spelling correctionsChris Samuel2009-03-301-1/+1
| | | | | | | | | Minor typo and spelling corrections fixed whilst reading to learn about cgroups capabilities. Signed-off-by: Chris Samuel <chris@csamuel.org> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* cgroups: consolidate cgroup documentsLi Zefan2009-01-161-0/+399
Move Documentation/cpusets.txt and Documentation/controllers/* to Documentation/cgroups/ Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>