Subject: + memcg-track-all-children-over-limit-in-the-root.patch added to -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
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 30 Jul 2013 15:34:01 -0700
The patch titled
Subject: memcg: track all children over limit in the root
has been added to the -mm tree. Its filename is
memcg-track-all-children-over-limit-in-the-root.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/memcg-track-all-children-over-limit-in-the-root.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/memcg-track-all-children-over-limit-in-the-root.patch
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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
@@ -865,9 +865,15 @@ 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);
}
@@ -6071,6 +6077,9 @@ 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
vmpressure-change-vmpressure-sr_lock-to-spinlock.patch
vmpressure-do-not-check-for-pending-work-to-prevent-from-new-work.patch
vmpressure-make-sure-there-are-no-events-queued-after-memcg-is-offlined.patch
vmpressure-make-sure-there-are-no-events-queued-after-memcg-is-offlined-checkpatch-fixes.patch
include-linux-schedh-dont-use-task-pid-tgid-in-same_thread_group-has_group_leader_pid.patch
watchdog-update-watchdog-attributes-atomically.patch
watchdog-update-watchdog_tresh-properly.patch
mm-fix-potential-null-pointer-dereference.patch
mm-hugetlb-move-up-the-code-which-check-availability-of-free-huge-page.patch
mm-hugetlb-trivial-commenting-fix.patch
mm-hugetlb-clean-up-alloc_huge_page.patch
mm-hugetlb-fix-and-clean-up-node-iteration-code-to-alloc-or-free.patch
mm-hugetlb-remove-redundant-list_empty-check-in-gather_surplus_pages.patch
mm-hugetlb-do-not-use-a-page-in-page-cache-for-cow-optimization.patch
mm-hugetlb-add-vm_noreserve-check-in-vma_has_reserves.patch
mm-hugetlb-remove-decrement_hugepage_resv_vma.patch
mm-hugetlb-decrement-reserve-count-if-vm_noreserve-alloc-page-cache.patch
memcg-remove-redundant-code-in-mem_cgroup_force_empty_write.patch
memcg-vmscan-integrate-soft-reclaim-tighter-with-zone-shrinking-code.patch
memcg-get-rid-of-soft-limit-tree-infrastructure.patch
vmscan-memcg-do-softlimit-reclaim-also-for-targeted-reclaim.patch
memcg-enhance-memcg-iterator-to-support-predicates.patch
memcg-track-children-in-soft-limit-excess-to-improve-soft-limit.patch
memcg-vmscan-do-not-attempt-soft-limit-reclaim-if-it-would-not-scan-anything.patch
memcg-track-all-children-over-limit-in-the-root.patch
memcg-vmscan-do-not-fall-into-reclaim-all-pass-too-quickly.patch
memcg-trivial-cleanups.patch
linux-next.patch
inode-convert-inode-lru-list-to-generic-lru-list-code-inode-move-inode-to-a-different-list-inside-lock.patch
list_lru-per-node-list-infrastructure-fix-broken-lru_retry-behaviour.patch
list_lru-remove-special-case-function-list_lru_dispose_all.patch
xfs-convert-dquot-cache-lru-to-list_lru-fix-dquot-isolation-hang.patch
list_lru-dynamically-adjust-node-arrays-super-fix-for-destroy-lrus.patch
staging-lustre-ldlm-convert-to-shrinkers-to-count-scan-api.patch
staging-lustre-obdclass-convert-lu_object-shrinker-to-count-scan-api.patch
staging-lustre-ptlrpc-convert-to-new-shrinker-api.patch
staging-lustre-libcfs-cleanup-linux-memh.patch
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