Hello, On Fri, Jun 21, 2024 at 12:10 PM Tejun Heo <tj@xxxxxxxxxx> wrote: > > Hello, > > On Thu, Jun 20, 2024 at 05:35:45PM -0700, David Rientjes wrote: > > As core counts are rapidly expanding over the next four years, Namhyung > > and I were looking at global locks that we're already seeing high > > contention on even today. > > > > Some of these are not MM specific: > > - cgroup_mutex > > Our machines are getting bigger but we aren't creating and destroying > cgroups frequently enough for this to matter. But yeah, I can see how this > can be a problem. > > > - cgroup_threadgroup_rwsem > > This one shouldn't matter at all in setups where new cgroups are populated > with CLONE_INTO_CGROUP and not migrated further. The lock isn't grabbed in > such usage pattern, which should be the vast majority already, I think. Are > you guys migrating tasks a lot or not using CLONE_INTO_CGROUP? I'm afraid there are still some use cases in Google that migrate processes and/or threads between cgroups. :( Thanks, Namhyung
