On Tue, 2016-02-09 at 18:56 +0100, Mike Galbraith wrote: > On Tue, 2016-02-09 at 12:54 -0500, Tejun Heo wrote: > > Hello, Mike. > > > > On Tue, Feb 09, 2016 at 06:04:04PM +0100, Mike Galbraith wrote: > > > workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask > > > CPUs > > > > > > WORK_CPU_UNBOUND work items queued to a bound workqueue always > > > run > > > locally. This is a good thing normally, but not when the user > > > has > > > asked us to keep unbound work away from certain CPUs. Round > > > robin > > > these to wq_unbound_cpumask CPUs instead, as perturbation > > > avoidance > > > trumps performance. > > > > I don't think doing this by default for everyone is a good idea. A > > lot of workqueue usages tend to touch whatever the scheduler was > > touching after all. Doing things per-cpu is generally a pretty > > good > > thing. > > It doesn't do anything unless the user twiddles the mask to exclude > certain (think no_hz_full) CPUs, so there are no clueless victims. (a plus: testers/robots can twiddle mask to help find bugs, _and_ nohz_full people can use it if they so choose) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html