diff options
| author | Tejun Heo <tj@kernel.org> | 2016-03-03 09:57:57 -0500 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2016-03-03 09:57:57 -0500 |
| commit | 20b454a61fba59be13de52b4493898583ea26d20 (patch) | |
| tree | 5ca01cf119f13dbd501886cecd917f0705382d96 /kernel/cgroup.c | |
| parent | 2378d8b8ba3d2adffb4f98c0c60ee2f448b3be69 (diff) | |
cgroup: suppress spurious de-populated events
During task migration, tasks may transfer between two css_sets which
are associated with the same cgroup. If those tasks are the only
tasks in the cgroup, this currently triggers a spurious de-populated
event on the cgroup.
Fix it by bumping up populated count before bumping it down during
migration to ensure that it doesn't reach zero spuriously.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Zefan Li <lizefan@huawei.com>
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index e97772b42dfb..5d452e7fcb4f 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -678,6 +678,9 @@ static void css_set_move_task(struct task_struct *task, { lockdep_assert_held(&css_set_lock); + if (to_cset && !css_set_populated(to_cset)) + css_set_update_populated(to_cset, true); + if (from_cset) { struct css_task_iter *it, *pos; @@ -711,8 +714,6 @@ static void css_set_move_task(struct task_struct *task, */ WARN_ON_ONCE(task->flags & PF_EXITING); - if (!css_set_populated(to_cset)) - css_set_update_populated(to_cset, true); rcu_assign_pointer(task->cgroups, to_cset); list_add_tail(&task->cg_list, use_mg_tasks ? &to_cset->mg_tasks : &to_cset->tasks); |