Re: [PATCH] mm: memcontrol: asynchronous reclaim for memory.high

[Michal Hocko]

On Wed 26-02-20 16:12:23, Yang Shi wrote:
[...]
> Actually I'm wondering if we really need account CPU cycles used by
> background reclaimer or not. For our usecase (this may be not general), the
> purpose of background reclaimer is to avoid latency sensitive workloads get
> into direct relcaim (avoid the stall from direct relcaim). In fact it just
> "steal" CPU cycles from lower priority or best-effort workloads to guarantee
> latency sensitive workloads behave well. If the "stolen" CPU cycles are
> accounted, it means the latency sensitive workloads would get throttled from
> somewhere else later, i.e. by CPU share.

I believe we need to because that work is not for free and so you are
essentially stealing those CPUs cycles from everybody else outside of
your throttled cgroup.
-- 
Michal Hocko
SUSE Labs