On Sat, Dec 17, 2022 at 11:05:25AM +0800, Yu Kuai wrote: > From: Yu Kuai <yukuai3@xxxxxxxxxx> > > bio will grab blkg reference, however, blkcg->online_pin is not grabbed, > hence cgroup can be removed after thread exit while bio is still in > progress. Bypass io in this case since it doesn't make sense to > throttle bio while cgroup is removed. I don't get it. Why wouldn't that make sense? ISTR some occasions where we clear the config to mitigate exits stalling for too long but in general a policy being active on a draining cgroup shouldn't be a problem. Thanks. -- tejun