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Date: Wed, 12 Aug 2009 13:58:06 +0200
From: Pavel Machek <pavel@ucw.cz>
To: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>, "Li, Shaohua" <shaohua.li@intel.com>,
       Gautham R Shenoy <ego@in.ibm.com>, Joel Schopp <jschopp@austin.ibm.com>,
       "Brown, Len" <len.brown@intel.com>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Balbir Singh <balbir@in.ibm.com>,
       Benjamin Herrenschmidt <benh@kernel.crashing.org>,
       Ingo Molnar <mingo@elte.hu>,
       Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
       Dipankar Sarma <dipankar@in.ibm.com>,
       "Darrick J. Wong" <djwong@us.ibm.com>,
       "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/3] cpu: idle state framework for offline CPUs.
Message-ID: <20090812115806.GK24339@elf.ucw.cz>
References: <20090805142311.553.78286.stgit@sofia.in.ibm.com> <20090806015855.GA20596@sli10-desk.sh.intel.com> <20090809120818.GA1338@ucw.cz> <200908091522.02898.rjw@sisk.pl> <20090810081941.GA18649@elf.ucw.cz> <1249950137.11545.38184.camel@localhost.localdomain>
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Hi!

> May be having (to pick a number) 3 possible offline states for all
> platforms with one for halt equivalent and one for deepest possible that
> CPU can handle and one for deepest possible that platform likes for
> C-states may make sense. Will keeps things simpler in terms of usage
> expectations and possibly reduce the misuse oppurtubity?

Maybe just going to the deepest offline state automatically is the
easiest option?

cpu hotplug/unplug should be rare-enough operation that the latencies
do not really matter, right?
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html