From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755949Ab0EDG4l (ORCPT ); Tue, 4 May 2010 02:56:41 -0400 Received: from hera.kernel.org ([140.211.167.34]:41341 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753175Ab0EDG4j (ORCPT ); Tue, 4 May 2010 02:56:39 -0400 Message-ID: <4BDFC4D9.4030408@kernel.org> Date: Tue, 04 May 2010 08:55:21 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: Peter Zijlstra CC: mingo@elte.hu, linux-kernel@vger.kernel.org, x86@kernel.org, oleg@redhat.com, rusty@rustcorp.com.au, sivanich@sgi.com, heiko.carstens@de.ibm.com, dipankar@in.ibm.com, josh@freedesktop.org, paulmck@linux.vnet.ibm.com, akpm@linux-foundation.org, arjan@linux.intel.com, torvalds@linux-foundation.org Subject: Re: [PATCH 1/4] cpu_stop: implement stop_cpu[s]() References: <1271952554-22368-1-git-send-email-tj@kernel.org> <1271952554-22368-2-git-send-email-tj@kernel.org> <1272893191.5605.121.camel@twins> <4BDFC16A.8070500@kernel.org> In-Reply-To: <4BDFC16A.8070500@kernel.org> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 04 May 2010 06:55:24 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, again. On 05/04/2010 08:40 AM, Tejun Heo wrote: > Oh, I had code piece which wanted to discern between -ENOENT from > non-excution and -ENOENT return from the work function which seems > gone now. I'll check things again and drop ->executed if everything > looks okay. Eh... now I remember. If we start with ->ret = 0, stop_cpus() can't return -ENOENT when none of the specified cpus executed without tracking execution status (so the current code). If we start with ->ret = -ENOENT, we can't tell whether all cpus executed successfully or none has executed unless we BUG_ON() -ENOENT return from work functions and let 0 return override -ENOENT. Thanks. -- tejun