- 08 Jan, 2009 40 commits
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Miao Xie authored
I found a bug on my dual-cpu box. I created a sub cpuset in top cpuset and assign 1 to its cpus. And then we attach some tasks into this sub cpuset. After this, we offline CPU1. Now, the tasks in this new cpuset are moved into top cpuset automatically because there is no cpu in sub cpuset. Then we online CPU1, we find all the tasks which doesn't belong to top cpuset originally just run on CPU0. We fix this bug by setting task's cpu_allowed to cpu_possible_map when attaching it into top cpuset. This method needn't modify the current behavior of cpusets on CPU hotplug, and all of tasks in top cpuset use cpu_possible_map to initialize their cpu_allowed. Signed-off-by:
Miao Xie <miaox@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>
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Lai Jiangshan authored
task_cs() calls task_subsys_state(). We must use rcu_read_lock() to protect cgroup_subsys_state(). It's correct that top_cpuset is never freed, but cgroup_subsys_state() accesses css_set, this css_set maybe freed when task_cs() called. We use use rcu_read_lock() to protect it. Signed-off-by:
Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by:
Paul Menage <menage@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by:
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Paul Menage authored
Add css_tryget(), that obtains a counted reference on a CSS. It is used in situations where the caller has a "weak" reference to the CSS, i.e. one that does not protect the cgroup from removal via a reference count, but would instead be cleaned up by a destroy() callback. css_tryget() will return true on success, or false if the cgroup is being removed. This is similar to Kamezawa Hiroyuki's patch from a week or two ago, but with the difference that in the event of css_tryget() racing with a cgroup_rmdir(), css_tryget() will only return false if the cgroup really does get removed. This implementation is done by biasing css->refcnt, so that a refcnt of 1 means "releasable" and 0 means "released or releasing". In the event of a race, css_tryget() distinguishes between "released" and "releasing" by checking for the CSS_REMOVED flag in css->flags. Signed-off-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:
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Paul Menage authored
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:
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Paul Menage authored
These patches introduce new locking/refcount support for cgroups to reduce the need for subsystems to call cgroup_lock(). This will ultimately allow the atomicity of cgroup_rmdir() (which was removed recently) to be restored. These three patches give: 1/3 - introduce a per-subsystem hierarchy_mutex which a subsystem can use to prevent changes to its own cgroup tree 2/3 - use hierarchy_mutex in place of calling cgroup_lock() in the memory controller 3/3 - introduce a css_tryget() function similar to the one recently proposed by Kamezawa, but avoiding spurious refcount failures in the event of a race between a css_tryget() and an unsuccessful cgroup_rmdir() Future patches will likely involve: - using hierarchy mutex in place of cgroup_lock() in more subsystems where appropriate - restoring the atomicity of cgroup_rmdir() with respect to cgroup_create() This patch: Add a hierarchy_mutex to the cgroup_subsys object that protects changes to the hierarchy observed by that subsystem. It is taken by the cgroup subsystem (in addition to cgroup_mutex) for the following operations: - linking a cgroup into that subsystem's cgroup tree - unlinking a cgroup from that subsystem's cgroup tree - moving the subsystem to/from a hierarchy (including across the bind() callback) Thus if the subsystem holds its own hierarchy_mutex, it can safely traverse its own hierarchy. Signed-off-by: -
KAMEZAWA Hiroyuki authored
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 authored
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:
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KAMEZAWA Hiroyuki authored
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: -
KAMEZAWA Hiroyuki authored
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: -
KAMEZAWA Hiroyuki authored
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:
Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by:
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Daisuke Nishimura authored
mem_cgroup_hierarchicl_reclaim() works properly even when !use_hierarchy now (by memcg-hierarchy-avoid-unnecessary-reclaim.patch), so, instead of try_to_free_mem_cgroup_pages(), it should be used in many cases. The only exception is force_empty. The group has no children in this case. Signed-off-by:
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Daisuke Nishimura authored
mpol_rebind_mm(), which can be called from cpuset_attach(), does down_write(mm->mmap_sem). This means down_write(mm->mmap_sem) can be called under cgroup_mutex. OTOH, page fault path does down_read(mm->mmap_sem) and calls mem_cgroup_try_charge_xxx(), which may eventually calls mem_cgroup_out_of_memory(). And mem_cgroup_out_of_memory() calls cgroup_lock(). This means cgroup_lock() can be called under down_read(mm->mmap_sem). If those two paths race, deadlock can happen. This patch avoid this deadlock by: - remove cgroup_lock() from mem_cgroup_out_of_memory(). - define new mutex (memcg_tasklist) and serialize mem_cgroup_move_task() (->attach handler of memory cgroup) and mem_cgroup_out_of_memory. Signed-off-by: -
Daisuke Nishimura authored
After previous patch, mem_cgroup_try_charge is not used by anyone, so we can remove it. Signed-off-by:
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Daisuke Nishimura authored
I think triggering OOM at mem_cgroup_prepare_migration would be just a bit overkill. Returning -ENOMEM would be enough for mem_cgroup_prepare_migration. The caller would handle the case anyway. Signed-off-by:
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KAMEZAWA Hiroyuki authored
Documentation for implementation details and how to test. Just an example. feel free to modify, add, remove lines. Signed-off-by:
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KAMEZAWA Hiroyuki authored
Show "real" limit of memcg. This helps my debugging and maybe useful for users. While testing hierarchy like this mount -t cgroup none /cgroup -t memory mkdir /cgroup/A set use_hierarchy==1 to "A" mkdir /cgroup/A/01 mkdir /cgroup/A/01/02 mkdir /cgroup/A/01/03 mkdir /cgroup/A/01/03/04 mkdir /cgroup/A/08 mkdir /cgroup/A/08/01 .... and set each own limit to them, "real" limit of each memcg is unclear. This patch shows real limit by checking all ancestors. Changelog: (v1) -> (v2) - remove "if" and use "min(a,b)" Acked-by:
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KOSAKI Motohiro authored
Currently, inactive_ratio of memcg is calculated at setting limit. because page_alloc.c does so and current implementation is straightforward porting. However, memcg introduced hierarchy feature recently. In hierarchy restriction, memory limit is not only decided memory.limit_in_bytes of current cgroup, but also parent limit and sibling memory usage. Then, The optimal inactive_ratio is changed frequently. So, everytime calculation is better. Tested-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by:
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KOSAKI Motohiro authored
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:
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KOSAKI Motohiro authored
Currently, mem_cgroup doesn't have own lock and almost its member doesn't need. (e.g. mem_cgroup->info is protected by zone lock, mem_cgroup->stat is per cpu variable) However, there is one explict exception. mem_cgroup->prev_priorit need lock, but doesn't protect. Luckly, this is NOT bug because prev_priority isn't used for current reclaim code. However, we plan to use prev_priority future again. Therefore, fixing is better. In addition, we plan to reuse this lock for another member. Then "reclaim_param_lock" name is better than "prev_priority_lock". Acked-by:
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KAMEZAWA Hiroyuki authored
Rename scan_global_lru() to scanning_global_lru(). Signed-off-by:
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KOSAKI Motohiro authored
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:
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KOSAKI Motohiro authored
Now, get_scan_ratio() return correct value although memcg reclaim. Then, mem_cgroup_calc_reclaim() can be removed. So, memcg reclaim get the same capability of anon/file reclaim balancing as global reclaim now. Acked-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@redhat.com> Acked-by:
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KOSAKI Motohiro authored
Introduce mem_cgroup_per_zone::reclaim_stat member and its statics collecting function. Now, get_scan_ratio() can calculate correct value on memcg reclaim. [hugh@veritas.com: avoid reclaim_stat oops when disabled] Acked-by:
Hugh Dickins <hugh@veritas.com> Signed-off-by:
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KOSAKI Motohiro authored
Introduce mem_cgroup_zone_nr_pages(). It is called by zone_nr_pages() helper function. This patch doesn't have any behavior change. Acked-by:
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:
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KOSAKI Motohiro authored
The inactive_anon_is_low() is key component of active/inactive anon balancing on reclaim. However current inactive_anon_is_low() function only consider global reclaim. Therefore, we need following ugly scan_global_lru() condition. if (lru == LRU_ACTIVE_ANON && (!scan_global_lru(sc) || inactive_anon_is_low(zone))) { shrink_active_list(nr_to_scan, zone, sc, priority, file); return 0; it cause that memcg reclaim always deactivate pages when shrink_list() is called. To make mem_cgroup_inactive_anon_is_low() improve active/inactive anon balancing of memcgroup. Acked-by: -
KOSAKI Motohiro authored
If CONFIG_CGROUP_MEM_RES_CTLR_SWAP=y, page_cgroup::mem_cgroup can be NULL. Therefore null checking is better. A later patch uses this function. Acked-by:
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KOSAKI Motohiro authored
Currently, get_scan_ratio() always calculate the balancing value for global reclaim and memcg reclaim doesn't use it. Therefore it doesn't have scan_global_lru() condition. However, we plan to expand get_scan_ratio() to be usable for memcg too, latter. Then, The dependency code of global reclaim in the get_scan_ratio() insert into scan_global_lru() condision explictly. This patch doesn't have any functional change. Acked-by:
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KOSAKI Motohiro authored
Add zone_nr_pages() helper function. It is used by a later patch. This patch doesn't have any functional change. Reviewed-by:
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KOSAKI Motohiro authored
Add zone_reclam_stat struct for later enhancement. A later patch uses this. This patch doesn't any behavior change (yet). Reviewed-by:
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KOSAKI Motohiro authored
The inactive_anon_is_low() is called only vmscan. Then it can move to vmscan.c This patch doesn't have any functional change. Reviewd-by:
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Daisuke Nishimura authored
If hierarchy is not used, no tree-walk is necessary. Reviewed-by:
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KAMEZAWA Hiroyuki authored
css's refcnt is dropped before end of following access. Hold it until end of access. Reported-by:
Li Zefan <lizf@cn.fujitsu.com> Signed-off-by:
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Daisuke Nishimura authored
There are scatterd calls of res_counter_check_under_limit(), and most of them don't take mem+swap accounting into account. define mem_cgroup_check_under_limit() and avoid direct use of res_counter_check_limit(). Reported-by:
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Nikanth Karthikesan authored
Remove unnecessary codes (...fragments of not-implemented functionalilty...) Reported-by:
Nikanth Karthikesan <knikanth@suse.de> Signed-off-by:
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KAMEZAWA Hiroyuki authored
My patch, memcg-fix-gfp_mask-of-callers-of-charge.patch changed gfp_mask of callers of charge to be GFP_HIGHUSER_MOVABLE for showing what will happen at memory reclaim. But in recent discussion, it's NACKed because it sounds ugly. This patch is for reverting it and add some clean up to gfp_mask of callers of charge. No behavior change but need review before generating HUNK in deep queue. This patch also adds explanation to meaning of gfp_mask passed to charge functions in memcontrol.h. Signed-off-by:
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KAMEZAWA Hiroyuki authored
check_under_limit logic was wrong and this check should be against mem_over_limit rather than mem. Reported-by:
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KAMEZAWA Hiroyuki authored
Current mmtom has new oom function as pagefault_out_of_memory(). It's added for select bad process rathar than killing current. When memcg hit limit and calls OOM at page_fault, this handler called and system-wide-oom handling happens. (means kernel panics if panic_on_oom is true....) To avoid overkill, check memcg's recent behavior before starting system-wide-oom. And this patch also fixes to guarantee "don't accnout against process with TIF_MEMDIE". This is necessary for smooth OOM. [akpm@linux-foundation.org: build fix] Signed-off-by:
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Lai Jiangshan authored
mm_match_cgroup() calls cgroup_subsys_state(). We must use rcu_read_lock() to protect cgroup_subsys_state(). Signed-off-by:
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Balbir Singh authored
Don't enable multiple hierarchy support by default. This patch introduces a features element that can be set to enable the nested depth hierarchy feature. This feature can only be enabled when the cgroup for which the feature this is enabled, has no children. Signed-off-by:
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Balbir Singh authored
This patch introduces hierarchical reclaim. When an ancestor goes over its limit, the charging routine points to the parent that is above its limit. The reclaim process then starts from the last scanned child of the ancestor and reclaims until the ancestor goes below its limit. [akpm@linux-foundation.org: coding-style fixes] [d-nishimura@mtf.biglobe.ne.jp: mem_cgroup_from_res_counter should handle both mem->res and mem->memsw] Signed-off-by:
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