linux/Documentation/cgroups, branch v3.6

mm/memcg: complete documentation for tcp memcg files

2012-08-01T01:42:43Z

Signed-off-by: Wanpeng Li Acked-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: rename config variables

2012-08-01T01:42:43Z

Sanity: CONFIG_CGROUP_MEM_RES_CTLR -> CONFIG_MEMCG CONFIG_CGROUP_MEM_RES_CTLR_SWAP -> CONFIG_MEMCG_SWAP CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED -> CONFIG_MEMCG_SWAP_ENABLED CONFIG_CGROUP_MEM_RES_CTLR_KMEM -> CONFIG_MEMCG_KMEM [mhocko@suse.cz: fix missed bits] Cc: Glauber Costa Acked-by: Michal Hocko Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: Hugh Dickins Cc: Tejun Heo Cc: Aneesh Kumar K.V Cc: David Rientjes Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

hugetlb/cgroup: add HugeTLB controller documentation

2012-08-01T01:42:41Z

Signed-off-by: Aneesh Kumar K.V Reviewed-by: KAMEZAWA Hiroyuki Cc: David Rientjes Cc: Hillf Danton Reviewed-by: Michal Hocko Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cgroup: Update remount documentation

2012-07-17T18:10:52Z

Remounting support will be removed in the future (see feature-removal-schedule.txt). Discourage users from using it. Signed-off-by: Daniel Wagner Signed-off-by: Tejun Heo Cc: Rob Landley Cc: Paul Menage Cc: Li Zefan Cc: Frederic Weisbecker Cc: KAMEZAWA Hiroyuki

cgroup: Remove populate() documentation

2012-07-09T16:56:23Z

This function was removed by 86f82d561864e902c70282b6f17cf590c0f34691. Signed-off-by: Daniel Wagner Signed-off-by: Tejun Heo Cc: Rob Landley Cc: Paul Menage Cc: Li Zefan Cc: Frederic Weisbecker Cc: KAMEZAWA Hiroyuki

cgroup: remove hierarchy_mutex

2012-06-07T02:12:30Z

It was introduced for memcg to iterate cgroup hierarchy without holding cgroup_mutex, but soon after that it was replaced with a lockless way in memcg. No one used hierarchy_mutex since that, so remove it. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo

memcg: move charges to root cgroup if use_hierarchy=0

2012-05-29T23:22:27Z

Presently, at removal of cgroup, ->pre_destroy() is called and moves charges to the parent cgroup. A major reason for returning -EBUSY from ->pre_destroy() is that the 'moving' hits the parent's resource limitation. It happens only when use_hierarchy=0. Considering use_hierarchy=0, all cgroups should be flat. So, no one cannot justify moving charges to parent...parent and children are in flat configuration, not hierarchical. This patch modifes the code to move charges to the root cgroup at rmdir/force_empty if use_hierarchy==0. This will much simplify rmdir() and reduce error in ->pre_destroy. Signed-off-by: KAMEZAWA Hiroyuki Cc: Aneesh Kumar K.V Cc: Michal Hocko Cc: Johannes Weiner Cc: Frederic Weisbecker Cc: Ying Han Cc: Glauber Costa Reviewed-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rescounters: add res_counter_uncharge_until()

2012-05-29T23:22:27Z

When killing a res_counter which is a child of other counter, we need to do res_counter_uncharge(child, xxx) res_counter_charge(parent, xxx) This is not atomic and wastes CPU. This patch adds res_counter_uncharge_until(). This function's uncharge propagates to ancestors until specified res_counter. res_counter_uncharge_until(child, parent, xxx) Now the operation is atomic and efficient. Signed-off-by: Frederic Weisbecker Signed-off-by: KAMEZAWA Hiroyuki Cc: Aneesh Kumar K.V Cc: Michal Hocko Cc: Johannes Weiner Cc: Ying Han Cc: Glauber Costa Reviewed-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: fix/change behavior of shared anon at moving task

2012-05-29T23:22:24Z

This patch changes memcg's behavior at task_move(). At task_move(), the kernel scans a task's page table and move the changes for mapped pages from source cgroup to target cgroup. There has been a bug at handling shared anonymous pages for a long time. Before patch: - The spec says 'shared anonymous pages are not moved.' - The implementation was 'shared anonymoys pages may be moved'. If page_mapcount <=2, shared anonymous pages's charge were moved. After patch: - The spec says 'all anonymous pages are moved'. - The implementation is 'all anonymous pages are moved'. Considering usage of memcg, this will not affect user's experience. 'shared anonymous' pages only exists between a tree of processes which don't do exec(). Moving one of process without exec() seems not sane. For example, libcgroup will not be affected by this change. (Anyway, no one noticed the implementation for a long time...) Below is a discussion log: - current spec/implementation are complex - Now, shared file caches are moved - It adds unclear check as page_mapcount(). To do correct check, we should check swap users, etc. - No one notice this implementation behavior. So, no one get benefit from the design. - In general, once task is moved to a cgroup for running, it will not be moved.... - Finally, we have control knob as memory.move_charge_at_immigrate. Here is a patch to allow moving shared pages, completely. This makes memcg simpler and fix current broken code. Suggested-by: Hugh Dickins Signed-off-by: KAMEZAWA Hiroyuki Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Naoya Horiguchi Cc: Glauber Costa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Documentation: memcg: future proof hierarchical statistics documentation

2012-05-29T23:22:20Z

The hierarchical versions of per-memcg counters in memory.stat are all calculated the same way and are all named total_. Documenting the pattern is easier for maintenance than listing each counter twice. Signed-off-by: Johannes Weiner Acked-by: Michal Hocko Acked-by: KOSAKI Motohiro Acked-by: Ying Han Randy Dunlap Acked-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds