On Thu, Mar 30, 2023 at 12:39 AM Michal Hocko <mhocko@xxxxxxxx> wrote: > > On Tue 28-03-23 22:16:42, Yosry Ahmed wrote: > > In workingset_refault(), we call > > mem_cgroup_flush_stats_atomic_ratelimited() to flush stats within an > > RCU read section and with sleeping disallowed. Move the call above > > the RCU read section and allow sleeping to avoid unnecessarily > > performing a lot of work without sleeping. > > Could you say few words why the flushing is done before counters are > updated rather than after (the RCU section)? It's not about the counters that are updated, it's about the counters that we read. Stats readers do a flush first to read accurate stats. We flush before a read, not after an update. > -- > Michal Hocko > SUSE Labs
