Messages in this thread | | | From | Valentin Schneider <> | Subject | Re: [PATCH 3/3] sched: Use cpu_dying() to fix balance_push vs hotplug-rollback | Date | Thu, 15 Apr 2021 15:32:11 +0100 |
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On 15/04/21 10:59, Peter Zijlstra wrote: > Can't make sense of what I did.. I've removed that hunk. Patch now looks > like this. >
Small nit below, but regardless feel free to apply to the whole lot: Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
@VincentD, ISTR you had tested the initial version of this with your fancy shmancy hotplug rollback stresser. Feel like doing this
> So instead, make sure balance_push is enabled between > sched_cpu_deactivate() and sched_cpu_activate() (eg. when > !cpu_active()), and gate it's utility with cpu_dying().
I'd word that "is enabled below sched_cpu_activate()", since sched_cpu_deactivate() is now out of the picture.
[...] > @@ -7639,6 +7639,9 @@ static DEFINE_PER_CPU(struct cpu_stop_wo > > /* > * Ensure we only run per-cpu kthreads once the CPU goes !active. > + * > + * This is active/set between sched_cpu_deactivate() / sched_cpu_activate().
Ditto
> + * But only effective when the hotplug motion is down. > */ > static void balance_push(struct rq *rq) > {
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