Re: [PATCH v3 1/1] cgroup: make per-cgroup pressure stall tracking configurable

[Suren Baghdasaryan]

On Tue, May 25, 2021 at 6:00 AM Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
>
> On Mon, May 24, 2021 at 12:53:39PM -0700, Suren Baghdasaryan wrote:
> > PSI accounts stalls for each cgroup separately and aggregates it at each
> > level of the hierarchy. This causes additional overhead with psi_avgs_work
> > being called for each cgroup in the hierarchy. psi_avgs_work has been
> > highly optimized, however on systems with large number of cgroups the
> > overhead becomes noticeable.
> > Systems which use PSI only at the system level could avoid this overhead
> > if PSI can be configured to skip per-cgroup stall accounting.
> > Add "cgroup_disable=pressure" kernel command-line option to allow
> > requesting system-wide only pressure stall accounting. When set, it
> > keeps system-wide accounting under /proc/pressure/ but skips accounting
> > for individual cgroups and does not expose PSI nodes in cgroup hierarchy.
> >
> > Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
>
> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Gentle ping for cgroup folks to please take a look at the cgroup interface part.