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> > kernel/sched/psi.c | 30 +++++++----- Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
