Re: [PATCH v2 1/2] sched: let the scheduler see CPU idle states

From: Peter Zijlstra
Date: Fri Sep 19 2014 - 11:11:54 EST


On Thu, Sep 18, 2014 at 10:39:25AM -0700, Paul E. McKenney wrote:
> On Thu, Sep 18, 2014 at 10:37:33AM -0700, Paul E. McKenney wrote:

> > A stop_cpus() will force a context switch on all CPUs, though it is
> > a rather big hammer.
>
> And I was reminded by the very next email that kick_all_cpus_sync() is
> another possibility -- it forces an interrupt on all online CPUs, idle
> or not.

I actually have a patch
http://lkml.kernel.org/r/1409815075-4180-2-git-send-email-chuansheng.liu@xxxxxxxxx
that changes that, because apparently there are idle loops that don't
actually exit on interrupt :-)

But yes, something like the wake_up_all_idle_cpus() should do.
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