On Tue 07-02-17 13:43:39, Vlastimil Babka wrote: [...] > > Anyway, shouldn't be it sufficient to disable preemption > > on drain_local_pages_wq? The CPU hotplug callback will not preempt us > > and so we cannot work on the same cpus, right? > > I thought the problem here was that the callback races with the work item > that has been migrated to a different cpu. Once we are not working on the > local cpu, disabling preempt/irq's won't help? If the worker is racing with the callback than only one of can run on a _particular_ cpu. So they cannot race. Or am I missing something? -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>