Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753900Ab1CYPgL (ORCPT ); Fri, 25 Mar 2011 11:36:11 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:59520 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750922Ab1CYPgJ (ORCPT >); Fri, 25 Mar 2011 11:36:09 -0400 Date: Fri, 25 Mar 2011 11:35:24 -0400 From: Konrad Rzeszutek Wilk To: Len Brown Cc: Trinabh Gupta , venki@google.com, ak@linux.intel.com, suresh.b.siddha@intel.com, sfr@canb.auug.org.au, peterz@infradead.org, benh@kernel.crashing.org, linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, arjan@linux.intel.com Subject: Re: [Xen-devel] Re: [RFC PATCH V4 2/5] cpuidle: list based cpuidle driver registration and selection Message-ID: <20110325153524.GN27651@dumpdata.com> References: <20110322123208.28725.30945.stgit@tringupt.in.ibm.com> <20110322123233.28725.92874.stgit@tringupt.in.ibm.com> <4D89BBDD.5090505@linux.vnet.ibm.com> <4D8B5197.2060306@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-Source-IP: acsmt356.oracle.com [141.146.40.156] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090207.4D8CB63D.0110,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1378 Lines: 32 On Fri, Mar 25, 2011 at 03:05:36AM -0400, Len Brown wrote: > > I think there are other problems too, related to saving and restoring > > of pm_idle pointer. For example, cpuidle itself saves current value > > of pm_idle, flips it and then restores the saved value. There is > > no guarantee that the saved function still exists. APM does exact > > same thing (though it may not be used these days). > > > > The problem also is that a number of architectures have copied the > > same design based on pm_idle; so its spreading. > > pm_idle is a primitive design yes, but I think the issue > with pm_idle is a theoretical one, at least on x86; > as there isn't any other code scribbling on pm_idle > in practice. So this is clean-up, rather than bug-fix work... > > > > It isn't immediately clear to me that all of these options > > > need to be preserved. > > > > So what do you suggest can be removed? > > I sent a series of small patches yesterday to get the ball rolling... > https://lkml.org/lkml/2011/3/24/54 > > I think the xen thing can go away. The xen thing being the setting of cpuidle to halt or the proposed patch? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/