Date: Wed, 12 Feb 2014 14:05:13 -0500 (EST)
From: Nicolas Pitre <nicolas.pitre@linaro.org>
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
cc: Arjan van de Ven <arjan@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Morten Rasmussen <Morten.Rasmussen@arm.com>,
        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, 12 Feb 2014, Lorenzo Pieralisi wrote:

> 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.

I would think this is meant to be called from architecture specific 
backend code.


Nicolas
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