Messages in this thread | | | From | Valentin Schneider <> | Subject | Re: [PATCH 1/2] sched: Make the idle task quack like a per-CPU kthread | Date | Tue, 11 May 2021 10:33:08 +0100 |
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On 11/05/21 09:32, Ingo Molnar wrote: > * Valentin Schneider <valentin.schneider@arm.com> wrote: >> AFAICT the extra calls are due to idle_thread_get() (used in cpuhp) >> calling init_idle(). However it looks to me that since >> >> 3bb5d2ee396a ("smp, idle: Allocate idle thread for each possible cpu during boot") >> >> we don't need to do that: we already have a >> >> for_each_possible_cpu(cpu) >> init_idle(cpu) >> >> issued at init. So can't we "simply" rely on that init-time creation, >> given it's done against the possible mask? I think the only thing that >> might need doing at later hotplug is making sure the preempt count is >> right (secondary startups seem to all prepare the idle task by issuing a >> preempt_disable()). > > Best-case it works, worst-case we discover an unclean assumption in the > init sequence and it works after we fix that. > > Win-win. :-) >
Well I got something that seems to work, let me it test it some more and convince myself it isn't completely bonkers and I'll toss it out.
> Thanks, > > Ingo
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