On Wed, Feb 02, 2022 at 10:31:03PM -0500, Waiman Long wrote: > 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@xxxxxxxxxx> Applied to cgroup/for-5.17-fixes. Thanks. -- tejun