Subject: [merged] memcg-track-all-children-over-limit-in-the-root.patch removed from -mm tree To: mhocko@xxxxxxx,bsingharora@xxxxxxxxx,glommer@xxxxxxxxxx,gthelen@xxxxxxxxxx,hannes@xxxxxxxxxxx,hughd@xxxxxxxxxx,kamezawa.hiroyu@xxxxxxxxxxxxxx,kosaki.motohiro@xxxxxxxxxxxxxx,tj@xxxxxxxxxx,walken@xxxxxxxxxx,yinghan@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Fri, 13 Sep 2013 13:02:14 -0700 The patch titled Subject: memcg: track all children over limit in the root has been removed from the -mm tree. Its filename was memcg-track-all-children-over-limit-in-the-root.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Michal Hocko <mhocko@xxxxxxx> Subject: memcg: track all children over limit in the root Children in soft limit excess are currently tracked up the hierarchy in memcg->children_in_excess. Nevertheless there still might exist tons of groups that are not in hierarchy relation to the root cgroup (e.g. all first level groups if root_mem_cgroup->use_hierarchy == false). As the whole tree walk has to be done when the iteration starts at root_mem_cgroup the iterator should be able to skip the walk if there is no child above the limit without iterating them. This can be done easily if the root tracks all children rather than only hierarchical children. This is done by this patch which updates root_mem_cgroup children_in_excess if root_mem_cgroup->use_hierarchy == false so the root knows about all children in excess. Please note that this is not an issue for inner memcgs which have use_hierarchy == false because then only the single group is visited so no special optimization is necessary. Signed-off-by: Michal Hocko <mhocko@xxxxxxx> Cc: Balbir Singh <bsingharora@xxxxxxxxx> Cc: Glauber Costa <glommer@xxxxxxxxxx> Cc: Greg Thelen <gthelen@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: Michel Lespinasse <walken@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Ying Han <yinghan@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff -puN mm/memcontrol.c~memcg-track-all-children-over-limit-in-the-root mm/memcontrol.c --- a/mm/memcontrol.c~memcg-track-all-children-over-limit-in-the-root +++ a/mm/memcontrol.c @@ -864,9 +864,15 @@ static void mem_cgroup_update_soft_limit /* * Necessary to update all ancestors when hierarchy is used * because their event counter is not touched. + * We track children even outside the hierarchy for the root + * cgroup because tree walk starting at root should visit + * all cgroups and we want to prevent from pointless tree + * walk if no children is below the limit. */ while (delta && (parent = parent_mem_cgroup(parent))) atomic_add(delta, &parent->children_in_excess); + if (memcg != root_mem_cgroup && !root_mem_cgroup->use_hierarchy) + atomic_add(delta, &root_mem_cgroup->children_in_excess); spin_unlock(&memcg->soft_lock); } @@ -6043,6 +6049,9 @@ static void mem_cgroup_css_offline(struc if (memcg->soft_contributed) { while ((memcg = parent_mem_cgroup(memcg))) atomic_dec(&memcg->children_in_excess); + + if (memcg != root_mem_cgroup && !root_mem_cgroup->use_hierarchy) + atomic_dec(&root_mem_cgroup->children_in_excess); } mem_cgroup_destroy_all_caches(memcg); vmpressure_cleanup(&memcg->vmpressure); _ Patches currently in -mm which might be from mhocko@xxxxxxx are origin.patch watchdog-update-watchdog-attributes-atomically.patch watchdog-update-watchdog_tresh-properly.patch watchdog-update-watchdog_tresh-properly-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html