Messages in this thread | | | Subject | Re: Crashes with 874bbfe600a6 in 3.18.25 | From | Mike Galbraith <> | Date | Tue, 09 Feb 2016 18:56:53 +0100 |
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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.
-Mike
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