Hello, Peter. On Thu, Mar 10, 2016 at 01:54:17PM +0100, Peter Zijlstra wrote: > > I've reproduced this on v4.4, but I've also managed to reproduce the bug > > after cherry-picking the following patches > > (all but one were marked for v4.4 stable): > > > > 6fe1f34 sched/cgroup: Fix cgroup entity load tracking tear-down > > d6e022f workqueue: handle NUMA_NO_NODE for unbound pool_workqueue lookup > > 041bd12 Revert "workqueue: make sure delayed work run in local cpu" > > 8bb5ef7 cgroup: make sure a parent css isn't freed before its children > > aa226ff cgroup: make sure a parent css isn't offlined before its children > > e93ad19 cpuset: make mm migration asynchronous > > Hmm, that is most unfortunate indeed. > > Can you describe a reliable reproducer? > > So we only call list_add_leaf_cfs_rq() through enqueue_task_fair(), > which means someone is still running inside that cgroup. > > TJ, I thought we only call offline when the cgroup is empty, don't we?
Yeap, populated csses shouldn't be being offlined. Thanks. -- tejun
