On 2013/4/17 1:10, Tejun Heo wrote: > Hello, Li. > > On Tue, Apr 16, 2013 at 07:17:17PM +0800, Li Zefan wrote: > ... >>> hot-unplug). It currently transfers all its tasks to the nearest >>> ancestor with executing resources, which is an irreversible process >>> which would affect all other co-mounted controllers. We probably want >>> it to just take on the masks of the ancestor until its own executing >>> resources become online again, and the new behavior should be gated >>> behind a switch (Li, can you please look into this?). >>> >> >> Sure, I'll be working on sane hierarchy behavior for cpuset. > > Great, it'd be great if you can share how it's gonna be done once the > basic design gets settled before full implementation. > The basic idea is, when a cpuset becomes empty due to hotplug, we don't move the tasks in it, but instead we update tasks' cpumask/nodemask using the nearest non-empty acestor cpuset's cpus_allowed and mems_allowed. - then it's allowed to move those tasks from the empty cpuset to another cpuset - when this acestor cpuset's cpumask/nodemask is changed (either by writing cpuset.cpus/mems or hotplug), not only the tasks in it but also tasks in the empty cpuset will be updated. - it's allowed to move a task to an empty cpuset, and the task's cpumask/nodemask will be updated according to the nearst non-empty acestor, no matter if this empty cpuset is exclusive or not. - if a previously offlined cpu becomes online again, the emtpy cpuset won't get this cpu resource automatically, which is the current behavior. How does this sound? _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
