Re: [PATCH 2/2] memcg: periodically flush the memcg stats

From: Tejun Heo
Date: Fri Jun 04 2021 - 22:34:29 EST


On Sat, Jun 05, 2021 at 09:54:21AM +0800, Hillf Danton wrote:
> The cond_resched() in cgroup_rstat_flush_locked() matches its appearence in
> your post [1]. So does unbound IMHO.

Ah yeah, this either needs CPU_INTENSIVE or UNBOUND, prolly the latter is
better.

> And the short stuff [2] looks to me like it is incorrect to queue a work
> acquiring mutex lock on to the system_wq. IOW the unbound wq is the right
> thing for any work that might sleep.

This part doesn't make sense. Blocking from per-cpu workqueue is completely
fine. What's not fine is consuming a lot of CPU cycles.

Thanks.

--
tejun