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Date: Mon, 15 Jun 2015 13:15:26 +0200
From: Borislav Petkov <bp@suse.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Huang Rui <ray.huang@amd.com>, Andy Lutomirski <luto@amacapital.net>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
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        Fengguang Wu <fengguang.wu@intel.com>, Aaron Lu <aaron.lu@intel.com>,
        Suravee Suthikulanit <suravee.suthikulpanit@amd.com>,
        Tony Li <tony.li@amd.com>, Ken Xue <ken.xue@amd.com>
Subject: Re: [PATCH v5 2/2] x86, mwaitt: introduce mwaix delay with a
 configurable timer
Message-ID: <20150615111526.GB4481@pd.tnic>
References: <1434365284-1495-1-git-send-email-ray.huang@amd.com>
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On Mon, Jun 15, 2015 at 12:57:18PM +0200, Peter Zijlstra wrote:
> Seeing how we disable C states, its unlikely to use less energy, so what
> exactly is its benefit, other than using fancy new instructions?

If the "disabling of C states" turns into a "go into a C-state which has
small wakeup latency" in the future, would be cool. Because we have a
bunch of places where we do delay.

Rui, what happens if you enter C1 instead? Any improvements or is the
wakeup latency too high?

Thanks.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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