On 05/31/2018 06:54 AM, Peter Zijlstra wrote: > On Tue, May 29, 2018 at 09:41:30AM -0400, Waiman Long wrote: > >> + cpuset.sched.load_balance >> + A read-write single value file which exists on non-root >> + cpuset-enabled cgroups. It is a binary value flag that accepts >> + either "0" (off) or "1" (on). This flag is set by the parent >> + and is not delegatable. It is on by default in the root cgroup. >> + >> + When it is on, tasks within this cpuset will be load-balanced >> + by the kernel scheduler. Tasks will be moved from CPUs with >> + high load to other CPUs within the same cpuset with less load >> + periodically. >> + >> + When it is off, there will be no load balancing among CPUs on >> + this cgroup. Tasks will stay in the CPUs they are running on >> + and will not be moved to other CPUs. > That is not entirely accurate I'm afraid (unless the patch makes it so, > I've yet to check). When you disable load-balancing on a cgroup you'll > get whatever balancing is left for the partition you happen to end up > in. > > Take for instance workqueue thingies, they use kthread_bind_mask() > (IIRC) and thus end up with PF_NO_SETAFFINITY so cpusets (or any other > cgroups really) do not have effect on them (long standing complaint). > > So take for instance the unbound numa enabled workqueue threads, those > will land in whatever partition and get balanced there. Thanks for the clarification. The patch doesn't make any changes in the scheduler. I was trying to say what the flag does. I will update the documentation about this nuisance. Cheers, Longman -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
