From mboxrd@z Thu Jan 1 00:00:00 1970 From: Len Brown Subject: Re: [patch 2/3] intel_idle: disable auto_demotion for hotplugged CPUs Date: Tue, 17 Jan 2012 14:22:03 -0500 Message-ID: <4F15CA5B.5050407@kernel.org> References: <20120110234820.B14B8100270@wpzn3.hot.corp.google.com> <201201171156.38490.trenn@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-vx0-f174.google.com ([209.85.220.174]:62351 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755514Ab2AQTWG (ORCPT ); Tue, 17 Jan 2012 14:22:06 -0500 Received: by vcbfo1 with SMTP id fo1so2085318vcb.19 for ; Tue, 17 Jan 2012 11:22:06 -0800 (PST) In-Reply-To: <201201171156.38490.trenn@suse.de> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: akpm@linux-foundation.org Cc: Thomas Renninger , linux-acpi@vger.kernel.org, shaohua.li@intel.com Andrew, Per reasoning from Thomas below, please drop this one. thanks, -Len On 01/17/2012 05:56 AM, Thomas Renninger wrote: > On Wednesday, January 11, 2012 12:48:20 AM akpm@linux-foundation.org wrote: >> From: Shaohua Li >> Subject: intel_idle: disable auto_demotion for hotplugged CPUs > > This one should not be necessary anymore with my intel_idle > patch series I have to rebase and resend (will do that after lunch). > > It provides a per cpu intel_idle init function which is called > from processor.ko in physical cpu hotplug case. > > From what I can see this patch does not change anything/much, because: > - CPUs onlined at bootup are initialized correctly already > - Soft offlining/onlining shouldn't matter in auto_demotion_disable > case as it's a HW MSR write and the CPU should still be in the > same state after off- and onlined again. > - Physically hotplugged/added CPUs are not registered with cpuidle > at all (this is what my patch series fixes), because intel_idle > does not offer any per cpu init() entry function. > With this patch they might be set into auto_demotion_disable now, > but no idle driver gets active for them. > > I'll pick up patch 1/3 and 3/3, base my patches on top and resend > everything, that should be easiest for everybody? > > Thomas >