| Subject | Re: [patch v4 02/18] sched: select_task_rq_fair clean up | From | Peter Zijlstra <> | Date | Tue, 12 Feb 2013 11:14:49 +0100 |
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On Thu, 2013-01-24 at 11:06 +0800, Alex Shi wrote: > It is impossible to miss a task allowed cpu in a eligible group.
I suppose your reasoning goes like: tsk->cpus_allowed is protected by ->pi_lock, we hold this, therefore it cannot change and find_idlest_group() dtrt?
We can then state that this is due to adding proper serialization to tsk->cpus_allowed.
> And since find_idlest_group only return a different group which > excludes old cpu, it's also impossible to find a new cpu same as old > cpu.
Sounds plausible, but I'm not convinced, do we have hard serialization against hotplug?
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