Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756496Ab3FSGSD (ORCPT ); Wed, 19 Jun 2013 02:18:03 -0400 Received: from mail-oa0-f41.google.com ([209.85.219.41]:58930 "EHLO mail-oa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752338Ab3FSGSA (ORCPT ); Wed, 19 Jun 2013 02:18:00 -0400 MIME-Version: 1.0 In-Reply-To: <1371619479-21386-1-git-send-email-chenxg@marvell.com> References: <1371619479-21386-1-git-send-email-chenxg@marvell.com> Date: Wed, 19 Jun 2013 11:48:00 +0530 Message-ID: Subject: Re: [PATCH v7] Cpufreq: Fix governor start/stop race condition From: Viresh Kumar To: Xiaoguang Chen Cc: rjw@sisk.pl, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, njiang1@marvell.com, zjwu@marvell.com, ylmao@marvell.com, chenxg.marvell@gmail.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 943 Lines: 23 On 19 June 2013 10:54, Xiaoguang Chen wrote: > Cpufreq governor's stop and start operation should be kept in sequence. > If not, there will be unexpected behavior, for example: > > There are 4 CPUs and policy->cpu=CPU0, CPU1/2/3 are linked to CPU0. > The normal sequence is as below: > > 1) Current governor is userspace, One application tries to set > governor to ondemand. It will call __cpufreq_set_policy in which it > will stop userspace governor and then start ondemand governor. > > 2) Current governor is userspace, Now CPU0 hotplugs in CPU3(put CPU3 online), You need a space before ( :( Otherwise looks good. Add my Acked-by: Viresh Kumar -- 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/