On Thu, 12 Jul 2018 13:29:42 -0400 Johannes Weiner <han...@cmpxchg.org> wrote:
> Right now, psi reports pressure and stall times of already concluded > stall events. For most use cases this is current enough, but certain > highly latency-sensitive applications, like the Android OOM killer, > might want to know about and react to stall states before they have > even concluded (e.g. a prolonged reclaim cycle). > > This patches the procfs/cgroupfs interface such that when the pressure > metrics are read, the current per-cpu states, if any, are taken into > account as well. > > Any ongoing states are concluded, their time snapshotted, and then > restarted. This requires holding the rq lock to avoid corruption. It > could use some form of rq lock ratelimiting or avoidance. > > Requested-by: Suren Baghdasaryan <sur...@google.com> > Not-yet-signed-off-by: Johannes Weiner <han...@cmpxchg.org> What-does-that-mean:?