aboutsummaryrefslogtreecommitdiff
path: root/Documentation/controllers
AgeCommit message (Collapse)Author
2009-01-15cgroups: consolidate cgroup documentsLi Zefan
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>
2009-01-08memcg: fix swap accounting leakKAMEZAWA Hiroyuki
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>
2009-01-08memcg: explain details and test documentKAMEZAWA Hiroyuki
Documentation for implementation details and how to test. Just an example. feel free to modify, add, remove lines. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Hugh Dickins <hugh@veritas.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>
2009-01-08memcg: swappinessKOSAKI Motohiro
Currently, /proc/sys/vm/swappiness can change swappiness ratio for global reclaim. However, memcg reclaim doesn't have tuning parameter for itself. In general, the optimal swappiness depend on workload. (e.g. hpc workload need to low swappiness than the others.) Then, per cgroup swappiness improve administrator tunability. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Hugh Dickins <hugh@veritas.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>
2009-01-08memcg: show reclaim statKOSAKI Motohiro
Add the following four fields to memory.stat file: - inactive_ratio - recent_rotated_anon - recent_rotated_file - recent_scanned_anon - recent_scanned_file Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Hugh Dickins <hugh@veritas.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>
2009-01-08memcg: memory cgroup hierarchy documentationBalbir Singh
Documentation updates for hierarchy support Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08memcg: mem+swap controller coreKAMEZAWA Hiroyuki
This patch implements per cgroup limit for usage of memory+swap. However there are SwapCache, double counting of swap-cache and swap-entry is avoided. Mem+Swap controller works as following. - memory usage is limited by memory.limit_in_bytes. - memory + swap usage is limited by memory.memsw_limit_in_bytes. This has following benefits. - A user can limit total resource usage of mem+swap. Without this, because memory resource controller doesn't take care of usage of swap, a process can exhaust all the swap (by memory leak.) We can avoid this case. And Swap is shared resource but it cannot be reclaimed (goes back to memory) until it's used. This characteristic can be trouble when the memory is divided into some parts by cpuset or memcg. Assume group A and group B. After some application executes, the system can be.. Group A -- very large free memory space but occupy 99% of swap. Group B -- under memory shortage but cannot use swap...it's nearly full. Ability to set appropriate swap limit for each group is required. Maybe someone wonder "why not swap but mem+swap ?" - The global LRU(kswapd) can swap out arbitrary pages. Swap-out means to move account from memory to swap...there is no change in usage of mem+swap. In other words, when we want to limit the usage of swap without affecting global LRU, mem+swap limit is better than just limiting swap. Accounting target information is stored in swap_cgroup which is per swap entry record. Charge is done as following. map - charge page and memsw. unmap - uncharge page/memsw if not SwapCache. swap-out (__delete_from_swap_cache) - uncharge page - record mem_cgroup information to swap_cgroup. swap-in (do_swap_page) - charged as page and memsw. record in swap_cgroup is cleared. memsw accounting is decremented. swap-free (swap_free()) - if swap entry is freed, memsw is uncharged by PAGE_SIZE. There are people work under never-swap environments and consider swap as something bad. For such people, this mem+swap controller extension is just an overhead. This overhead is avoided by config or boot option. (see Kconfig. detail is not in this patch.) TODO: - maybe more optimization can be don in swap-in path. (but not very safe.) But we just do simple accounting at this stage. [nishimura@mxp.nes.nec.co.jp: make resize limit hold mutex] [hugh@veritas.com: memswap controller core swapcache fixes] 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: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08memcg: handle swap cachesKAMEZAWA Hiroyuki
SwapCache support for memory resource controller (memcg) Before mem+swap controller, memcg itself should handle SwapCache in proper way. This is cut-out from it. In current memcg, SwapCache is just leaked and the user can create tons of SwapCache. This is a leak of account and should be handled. SwapCache accounting is done as following. charge (anon) - charged when it's mapped. (because of readahead, charge at add_to_swap_cache() is not sane) uncharge (anon) - uncharged when it's dropped from swapcache and fully unmapped. means it's not uncharged at unmap. Note: delete from swap cache at swap-in is done after rmap information is established. charge (shmem) - charged at swap-in. this prevents charge at add_to_page_cache(). uncharge (shmem) - uncharged when it's dropped from swapcache and not on shmem's radix-tree. at migration, check against 'old page' is modified to handle shmem. Comparing to the old version discussed (and caused troubles), we have advantages of - PCG_USED bit. - simple migrating handling. So, situation is much easier than several months ago, maybe. [hugh@veritas.com: memcg: handle swap caches build fix] Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08memcg: new force_empty to free pages under groupKAMEZAWA Hiroyuki
By memcg-move-all-accounts-to-parent-at-rmdir.patch, there is no leak of memory usage and force_empty is removed. This patch adds "force_empty" again, in reasonable manner. memory.force_empty file works when #echo 0 (or some) > memory.force_empty and have following function. 1. only works when there are no task in this cgroup. 2. free all page under this cgroup as much as possible. 3. page which cannot be freed will be moved up to parent. 4. Then, memcg will be empty after above echo returns. This is much better behavior than old "force_empty" which just forget all accounts. This patch also check signal_pending() and above "echo" can be stopped by "Ctrl-C". [akpm@linux-foundation.org: cleanup] 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: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08memcg: move all acccounting to parent at rmdir()KAMEZAWA Hiroyuki
This patch provides a function to move account information of a page between mem_cgroups and rewrite force_empty to make use of this. This moving of page_cgroup is done under - lru_lock of source/destination mem_cgroup is held. - lock_page_cgroup() is held. Then, a routine which touches pc->mem_cgroup without lock_page_cgroup() should confirm pc->mem_cgroup is still valid or not. Typical code can be following. (while page is not under lock_page()) mem = pc->mem_cgroup; mz = page_cgroup_zoneinfo(pc) spin_lock_irqsave(&mz->lru_lock); if (pc->mem_cgroup == mem) ...../* some list handling */ spin_unlock_irqrestore(&mz->lru_lock); Of course, better way is lock_page_cgroup(pc); .... unlock_page_cgroup(pc); But you should confirm the nest of lock and avoid deadlock. If you treats page_cgroup from mem_cgroup's LRU under mz->lru_lock, you don't have to worry about what pc->mem_cgroup points to. moved pages are added to head of lru, not to tail. Expected users of this routine is: - force_empty (rmdir) - moving tasks between cgroup (for moving account information.) - hierarchy (maybe useful.) force_empty(rmdir) uses this move_account and move pages to its parent. This "move" will not cause OOM (I added "oom" parameter to try_charge().) If the parent is busy (not enough memory), force_empty calls try_to_free_page() and reduce usage. Purpose of this behavior is - Fix "forget all" behavior of force_empty and avoid leak of accounting. - By "moving first, free if necessary", keep pages on memory as much as possible. Adding a switch to change behavior of force_empty to - free first, move if necessary - free all, if there is mlocked/busy pages, return -EBUSY. is under consideration. (I'll add if someone requtests.) This patch also removes memory.force_empty file, a brutal debug-only interface. Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Tested-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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-11sched: add hierarchical accounting to cpu accounting controllerBharata B Rao
Impact: improve CPU time accounting of tasks under the cpu accounting controller Add hierarchical accounting to cpu accounting controller and include cpuacct documentation. Currently, while charging the task's cputime to its accounting group, the accounting group hierarchy isn't updated. This patch charges the cputime of a task to its accounting group and all its parent accounting groups. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Reviewed-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-20memcg: avoid accounting special pagesKAMEZAWA Hiroyuki
There are not-on-LRU pages which can be mapped and they are not worth to be accounted. (becasue we can't shrink them and need dirty codes to handle specical case) We'd like to make use of usual objrmap/radix-tree's protcol and don't want to account out-of-vm's control pages. When special_mapping_fault() is called, page->mapping is tend to be NULL and it's charged as Anonymous page. insert_page() also handles some special pages from drivers. This patch is for avoiding to account special pages. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
2008-07-25memcg: limit change shrink usageKAMEZAWA Hiroyuki
Shrinking memory usage at limit change. [akpm@linux-foundation.org: coding-style fixes] Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.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>
2008-07-04devcgroup: fix odd behaviour when writing 'a' to devices.allowLi Zefan
# cat /devcg/devices.list a *:* rwm # echo a > devices.allow # cat /devcg/devices.list a *:* rwm a 0:0 rwm This is odd and maybe confusing. With this patch, writing 'a' to devices.allow will add 'a *:* rwm' to the whitelist. Also a few fixes and updates to the document. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29memcgroups: add a document describing the resource counter abstractionPavel Emelyanov
The resource counter is supposed to facilitate the resource accounting of arbitrary resource (and it already does this for memory controller). However, it is about to be used in other resources controllers (swap, kernel memory, networking, etc), so provide a doc describing how to work with it. This will eliminate all the possible future duplications in the appropriate controllers' docs. Fixed errors pointed out by Randy. [akpm@linux-foundation.org: fix documentation tpyo] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2008-04-29cgroups: implement device whitelistSerge E. Hallyn
Implement a cgroup to track and enforce open and mknod restrictions on device files. A device cgroup associates a device access whitelist with each cgroup. A whitelist entry has 4 fields. 'type' is a (all), c (char), or b (block). 'all' means it applies to all types and all major and minor numbers. Major and minor are either an integer or * for all. Access is a composition of r (read), w (write), and m (mknod). The root device cgroup starts with rwm to 'all'. A child devcg gets a copy of the parent. Admins can then remove devices from the whitelist or add new entries. A child cgroup can never receive a device access which is denied its parent. However when a device access is removed from a parent it will not also be removed from the child(ren). An entry is added using devices.allow, and removed using devices.deny. For instance echo 'c 1:3 mr' > /cgroups/1/devices.allow allows cgroup 1 to read and mknod the device usually known as /dev/null. Doing echo a > /cgroups/1/devices.deny will remove the default 'a *:* mrw' entry. CAP_SYS_ADMIN is needed to change permissions or move another task to a new cgroup. A cgroup may not be granted more permissions than the cgroup's parent has. Any task can move itself between cgroups. This won't be sufficient, but we can decide the best way to adequately restrict movement later. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix may-be-used-uninitialized warning] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: James Morris <jmorris@namei.org> Looks-good-to: Pavel Emelyanov <xemul@openvz.org> Cc: Daniel Hokka Zakrisson <daniel@hozac.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04Memory controller: rename to Memory Resource ControllerBalbir Singh
Rename Memory Controller to Memory Resource Controller. Reflect the same changes in the CONFIG definition for the Memory Resource Controller. Group together the config options for Resource Counters and Memory Resource Controller. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.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>
2008-03-04Memory Resource Controller use strstrip while parsing argumentsBalbir Singh
The memory controller has a requirement that while writing values, we need to use echo -n. This patch fixes the problem and makes the UI more consistent. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.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>
2008-02-23memcgroup: fix and update documentationLi Zefan
- remove trailing " Bytes"s in the demonstration - remove section 4.4 (feature control_type has been removed) - fix reference section Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07update Documentation/controller/memory.txtKAMEZAWA Hiroyuki
Documentation updates for memory controller. 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>
2008-02-07Memory controller improve user interfaceBalbir Singh
Change the interface to use bytes instead of pages. Page sizes can vary across platforms and configurations. A new strategy routine has been added to the resource counters infrastructure to format the data as desired. Suggested by David Rientjes, Andrew Morton and Herbert Poetzl Tested on a UML setup with the config for memory control enabled. [kamezawa.hiroyu@jp.fujitsu.com: possible race fix in res_counter] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@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>
2008-02-07Memory controller: add documentBalbir Singh
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: David Rientjes <rientjes@google.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>