Hello, This patchset implement proper hierarchy support for cgroup_freezer as discussed in "[RFC] cgroup TODOs"[1]. The patchset first implements generic cgroup iteration macros - cgroup_for_each_children(), cgroup_for_each_descendant_{pre|post}(). Combined with the newly introduced ->post_create() callback, this allows controllers to implement reliable iteration over descendants without messing with cgroup internal locking. Controllers can perform reliable walking using simple hierarchy-wide locking or finer-grained parent-children locking. Using the iteration macros and ->post_create(), cgroup_freezer is updated to propagate state updates to and collect FROZEN completions from the descendants. This removes .broken_hierarchy marking from cgroup_freezer. cgroup_freezer hierarchy support is implemented using finer-grained locking not necessarily because it's necessary but more because I wanted an example controller doing that. This patchset contains the following nine patches. 0001-cgroup-add-cgroup_subsys-post_create.patch 0002-cgroup-Use-rculist-ops-for-cgroup-children.patch 0003-cgroup-implement-generic-child-descendant-walk-macro.patch 0004-cgroup_freezer-trivial-cleanups.patch 0005-cgroup_freezer-prepare-freezer_change_state-for-full.patch 0006-cgroup_freezer-make-freezer-state-mask-of-flags.patch 0007-cgroup_freezer-introduce-CGROUP_FREEZING_-SELF-PAREN.patch 0008-cgroup_freezer-add-post_create-and-pre_destroy-and-t.patch 0009-cgroup_freezer-implement-proper-hierarchy-support.patch 0001-0003 implement cgroup descendant iterators. 0004-0008 prepare cgroup_freezer for hierarchy support. 0009 implements it. This patchset is on top of v3.6 (a0d271cbfe) + [2] the first three patches of "memcg/cgroup: do not fail fail on pre_destroy callbacks" patchset + [3] "cgroup: simplify cgroup removal path" v2 patchset with cgroup/for-3.8 pulled into it. The branch is rather floaty at the moment so it would be the easiest to pull the following branch for review. git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-cgroup_freezer-hierarchy Thanks. kernel/cgroup.c | 106 +++++++++++++- kernel/cgroup_freezer.c | 359 +++++++++++++++++++++++++++++++++++------------- 3 files changed, 445 insertions(+), 104 deletions(-) -- tejun [1] http://thread.gmane.org/gmane.linux.kernel.containers/23698 [2] http://thread.gmane.org/gmane.linux.kernel.cgroups/4757 [3] http://thread.gmane.org/gmane.linux.kernel.cgroups/4861 _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers