[PATCH v2] irqchip: gic: Allow gic_arch_extn hooks to call into scheduler

Nicolas Pitre nicolas.pitre at linaro.org
Tue Aug 12 17:49:34 PDT 2014


On Tue, 12 Aug 2014, Stephen Boyd wrote:

> On 08/12/14 17:39, Nicolas Pitre wrote:
> > On Tue, 12 Aug 2014, Stephen Boyd wrote:
> >
> >> On 08/05/14 19:34, Nicolas Pitre wrote:
> >>>> It allows us to synchronize with another CPU that may be inside
> >>>> gic_raise_softirq(). If the other CPU was in that function then this CPU
> >>>> would wait until it was done sending the IPI to continue along and
> >>>> reroute them. If the other CPU was just about to grab the sgi lock then
> >>>> we would guarantee that the CPU would see the new gic_cpu_map value and
> >>>> thus any redirection is not necessary.
> >>> OK I get it now.
> >>>
> >>>> I hoped that the commit text explained this.
> >>> I'm possibly not bright enough to get it the first time.
> >>>
> >>>> Honestly it probably isn't a noticeable performance boost either way 
> >>>> but I think this is the best we can do.
> >>> Sure, agreed.
> >>>
> >>>
> >>>
> >> Ok, so which patch is preferred?
> > I'd say the later.
> >
> >
> 
> Sorry, it's not clear. I'll send v3 and hopefully it will be the right one.

Certainly the best way to disambiguate things.


Nicolas



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