Date: Wed, 12 Feb 2014 17:37:59 +0000
From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Arjan van de Ven <arjan@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
        Morten Rasmussen <Morten.Rasmussen@arm.com>,
        Nicolas Pitre <nicolas.pitre@linaro.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Preeti U Murthy <preeti@linux.vnet.ibm.com>,
        Len Brown <len.brown@intel.com>, Preeti Murthy <preeti.lkml@gmail.com>,
        "mingo@redhat.com" <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        LKML <linux-kernel@vger.kernel.org>,
        "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
        Lists linaro-kernel <linaro-kernel@lists.linaro.org>
Subject: Re: [RFC PATCH 3/3] idle: store the idle state index in the struct rq
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On Wed, Feb 12, 2014 at 04:14:38PM +0000, Arjan van de Ven wrote:
> 
> >> sched_cpu_cache_wiped(int llc)
> >>
> >> that would be very nice for this; the menuidle side knows this
> >> for some cases and thus can just call it. This would be a very
> >> small and minimal change
> >
> > What do you mean by "menuidle side knows this for some cases" ?
> > You mean you know that some C-state entries imply llc clean/invalidate ?
> 
> in the architectural idle code we can know if the llc got flushed
> there's also the per core flags where we know with reasonable certainty
> that the per core caches got flushed.

Ok, but that's arch specific, not something we can detect from the menu
governor in generic code , that's what I wanted to ask because it was not
clear.

Thanks,
Lorenzo

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