From: Len Brown <lenb@kernel.org>
To: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: linux-pm@lists.linux-foundation.org, x86@kernel.org,
linux-acpi@vger.kernel.org
Subject: Re: [PATCH] intel_idle: disable HW auto-demotion
Date: Wed, 16 Feb 2011 01:19:18 -0500 (EST) [thread overview]
Message-ID: <alpine.LFD.2.02.1102160115160.843@x980> (raw)
In-Reply-To: <20110119144152.GA23020@srcf.ucam.org>
On Wed, 19 Jan 2011, Matthew Garrett wrote:
> On Tue, Jan 18, 2011 at 09:52:26PM -0500, Len Brown wrote:
> > + * Disable HW auto demotion on tick-less idle kernels
> > + */
> > +static unsigned int has_nhm_snb_hw_auto_demotion;
> > +#ifdef CONFIG_NO_HZ
> > +static unsigned int auto_demotion;
> > +#else
> > +static unsigned int auto_demotion = 1;
> > +#endif
>
> What if someone boots with nohz=off?
The next version of this patch will disable auto-demotion
independent of HZ, on the assumption that the governor
is smart enough today to get what it asks for, HZ or NO_HZ.
It is also now limits the change to NHM/WSM,
as SNB has auto-un-demotion to address this scenario.
> Just so I'm clear on this - this is unrelated to the auto-popup on DMA,
> right?
Right, C2 popup is a different feature, and that is smart
enought to return to the power saving state after the
DMA is done.
cheers,
Len Brown, Intel Open Source Technology Center
prev parent reply other threads:[~2011-02-16 6:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-19 2:52 [PATCH] intel_idle: disable HW auto-demotion Len Brown
2011-01-19 5:40 ` [PATCH] intel_idle: disable HW auto-demotion by default (v2) Len Brown
2011-02-16 6:22 ` [PATCH] intel_idle: disable NHM/WSM HW C-state auto-demotion (v3) Len Brown
2011-02-27 16:17 ` Pierre Tardy
2011-02-28 16:08 ` Len Brown
2011-01-19 14:41 ` [PATCH] intel_idle: disable HW auto-demotion Matthew Garrett
2011-02-16 6:19 ` Len Brown [this message]
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