Waiman Long f5afdefe18 cgroup/cpuset: Fix "suspicious RCU usage" lockdep warning
commit 2bdfd2825c9662463371e6691b1a794e97fa36b4 upstream.

It was found that a "suspicious RCU usage" lockdep warning was issued
with the rcu_read_lock() call in update_sibling_cpumasks().  It is
because the update_cpumasks_hier() function may sleep. So we have
to release the RCU lock, call update_cpumasks_hier() and reacquire
it afterward.

Also add a percpu_rwsem_assert_held() in update_sibling_cpumasks()
instead of stating that in the comment.

Fixes: 4716909cc5c5 ("cpuset: Track cpusets that use parent's effective_cpus")
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08 18:34:14 +01:00
..
2021-09-02 13:00:15 -07:00
2021-08-11 13:11:12 -07:00
2021-09-08 15:32:35 -07:00
2021-06-18 11:43:08 +02:00
2021-09-08 15:32:34 -07:00
2021-05-07 00:26:33 -07:00
2021-06-18 11:43:09 +02:00
2021-08-11 14:47:16 +02:00
2021-05-07 00:26:34 -07:00