cgroup/cpuset: Wake up cpuset_attach_wq tasks in cpuset_cancel_attach()
authorWaiman Long <longman@redhat.com>
Tue, 11 Apr 2023 13:35:57 +0000 (09:35 -0400)
committerTejun Heo <tj@kernel.org>
Wed, 12 Apr 2023 18:23:58 +0000 (08:23 -1000)
commitba9182a89626d5f83c2ee4594f55cb9c1e60f0e2
treec932a0a2c3b593f3f4d6ffd90bcffbb6dad9cdc9
parent57dcd64c7e036299ef526b400a8d12b8a2352f26
cgroup/cpuset: Wake up cpuset_attach_wq tasks in cpuset_cancel_attach()

After a successful cpuset_can_attach() call which increments the
attach_in_progress flag, either cpuset_cancel_attach() or cpuset_attach()
will be called later. In cpuset_attach(), tasks in cpuset_attach_wq,
if present, will be woken up at the end. That is not the case in
cpuset_cancel_attach(). So missed wakeup is possible if the attach
operation is somehow cancelled. Fix that by doing the wakeup in
cpuset_cancel_attach() as well.

Fixes: e44193d39e8d ("cpuset: let hotplug propagation work wait for task attaching")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Cc: stable@vger.kernel.org # v3.11+
Signed-off-by: Tejun Heo <tj@kernel.org>
kernel/cgroup/cpuset.c