On 04/03/20 10:55, Tejun Heo wrote: > On Thu, Mar 26, 2020 at 10:15:32AM +0000, Qais Yousef wrote: > > On 03/25/20 15:19, Tejun Heo wrote: > > > On Wed, Mar 25, 2020 at 03:16:56PM -0400, Qian Cai wrote: > > > > The linux-next commit a49e4629b5ed (“cpuset: Make cpuset hotplug synchronous”) > > > > introduced real deadlocks with CPU hotplug as showed in the lockdep splat, since it is > > > > now making a relation from cpu_hotplug_lock —> cgroup_mutex. > > > > > > Prateek, can you please take a look? Given that the merge window is just around > > > the corner, we might have to revert and retry later if it can't be resolved > > > quickly. > > > > I've ran cpuset_hotplug and cpuhotplug LTP tests using next-20200325 but > > couldn't reproduce it. > > > > Hopefully that can be fixed, but if you had to revert it, do you mind picking > > this instead to fix the LTP issue I encountered before? > > > > https://lore.kernel.org/lkml/20200211141554.24181-1-qais.yousef@xxxxxxx/ > > So, I'd rather not, for now anyway. It isn't a real problem and I don't wanna > add a wait vector there. What would be the right approach to get a fix in then? We have been skipping this test for a while and we'd like to enable it but this failure is a blocking issue. Android relies on cpuset and some devices use hotplug to manage thermal/power. So it's an interesting combination to be able to test for us. Thanks -- Qais Yousef
