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Date: Wed, 11 Dec 2013 17:43:18 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>, Mike Galbraith <bitbucket@online.de>,
        Thomas Gleixner <tglx@linutronix.de>, Len Brown <lenb@kernel.org>,
        Linux PM list <linux-pm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Jeremy Eder <jeder@redhat.com>, x86@kernel.org
Subject: Re: 50 Watt idle power regression bisected to Linux-3.10
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On Wed, Dec 11, 2013 at 03:56:55PM +0100, Ingo Molnar wrote:
> 
> * Borislav Petkov <bp@alien8.de> wrote:
> 
> > On Wed, Dec 11, 2013 at 01:43:52PM +0100, Peter Zijlstra wrote:
> > > Something like the below.. someone needs to double check and possibly
> > > add SNB/IVB EX parts if they're already available.
> > 
> > Right, our friends at Intel would need to tell us which families/models
> > does AAI65 span... if, this is actually the case.
> 
> I think CLFLUSH should be pretty universally available, IIRC graphics 
> drivers were using it rather heavily in combination with 
> write-combining MTRRs, both on Linux and on Windows.

The availability isn't the problem; the cost is. We shouldn't issue one
if its not required. Only 'broken' EX hardware needs it.