From 0679dee03c6d706d57145ea92c23d08fa10a1999 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Wed, 2 Aug 2017 17:55:29 +0100 Subject: cgroup: keep track of number of descent cgroups Keep track of the number of online and dying descent cgroups. This data will be used later to add an ability to control cgroup hierarchy (limit the depth and the number of descent cgroups) and display hierarchy stats. Signed-off-by: Roman Gushchin Suggested-by: Tejun Heo Signed-off-by: Tejun Heo Cc: Zefan Li Cc: Waiman Long Cc: Johannes Weiner Cc: kernel-team@fb.com Cc: cgroups@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- kernel/cgroup/cgroup.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'kernel/cgroup/cgroup.c') diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 85f6a112344b..cfdbb1e780de 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4408,9 +4408,15 @@ static void css_release_work_fn(struct work_struct *work) if (ss->css_released) ss->css_released(css); } else { + struct cgroup *tcgrp; + /* cgroup release path */ trace_cgroup_release(cgrp); + for (tcgrp = cgroup_parent(cgrp); tcgrp; + tcgrp = cgroup_parent(tcgrp)) + tcgrp->nr_dying_descendants--; + cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id); cgrp->id = -1; @@ -4609,9 +4615,13 @@ static struct cgroup *cgroup_create(struct cgroup *parent) cgrp->root = root; cgrp->level = level; - for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) + for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) { cgrp->ancestor_ids[tcgrp->level] = tcgrp->id; + if (tcgrp != cgrp) + tcgrp->nr_descendants++; + } + if (notify_on_release(parent)) set_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags); @@ -4817,7 +4827,7 @@ static void kill_css(struct cgroup_subsys_state *css) static int cgroup_destroy_locked(struct cgroup *cgrp) __releases(&cgroup_mutex) __acquires(&cgroup_mutex) { - struct cgroup *parent = cgroup_parent(cgrp); + struct cgroup *tcgrp, *parent = cgroup_parent(cgrp); struct cgroup_subsys_state *css; struct cgrp_cset_link *link; int ssid; @@ -4865,6 +4875,11 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) if (parent && cgroup_is_threaded(cgrp)) parent->nr_threaded_children--; + for (tcgrp = cgroup_parent(cgrp); tcgrp; tcgrp = cgroup_parent(tcgrp)) { + tcgrp->nr_descendants--; + tcgrp->nr_dying_descendants++; + } + cgroup1_check_for_release(cgroup_parent(cgrp)); /* put the base reference */ -- cgit