Re: [RFC Patch] perf_event: fix a cgroup switch warning

2019-05-14 Thread Cong Wang
On Tue, May 14, 2019 at 5:32 AM Peter Zijlstra wrote: > > On Mon, May 13, 2019 at 05:27:47PM -0700, Cong Wang wrote: > > We have been consistently triggering the warning > > WARN_ON_ONCE(cpuctx->cgrp) in perf_cgroup_switch() for a rather > > long time, although we still have no clue on how to repr

Re: [RFC Patch] perf_event: fix a cgroup switch warning

2019-05-14 Thread Peter Zijlstra
On Mon, May 13, 2019 at 05:27:47PM -0700, Cong Wang wrote: > We have been consistently triggering the warning > WARN_ON_ONCE(cpuctx->cgrp) in perf_cgroup_switch() for a rather > long time, although we still have no clue on how to reproduce it. > > Looking into the code, it seems the only possibili

[RFC Patch] perf_event: fix a cgroup switch warning

2019-05-13 Thread Cong Wang
We have been consistently triggering the warning WARN_ON_ONCE(cpuctx->cgrp) in perf_cgroup_switch() for a rather long time, although we still have no clue on how to reproduce it. Looking into the code, it seems the only possibility here is that the process calling perf_event_open() with a cgroup t