Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932996Ab2JWNOc (ORCPT ); Tue, 23 Oct 2012 09:14:32 -0400 Received: from mail.skyhub.de ([78.46.96.112]:35767 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932625Ab2JWNOb (ORCPT ); Tue, 23 Oct 2012 09:14:31 -0400 Date: Tue, 23 Oct 2012 15:14:28 +0200 From: Borislav Petkov To: Miao Xie Cc: Tang Chen , tony.luck@intel.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, laijs@cn.fujitsu.com, wency@cn.fujitsu.com, x86@kernel.org, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] Replace if statement with WARN_ON_ONCE() in cmci_rediscover(). Message-ID: <20121023131428.GA26756@x1.osrc.amd.com> Mail-Followup-To: Borislav Petkov , Miao Xie , Tang Chen , tony.luck@intel.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, laijs@cn.fujitsu.com, wency@cn.fujitsu.com, x86@kernel.org, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org References: <1350625528-1385-1-git-send-email-tangchen@cn.fujitsu.com> <1350625528-1385-2-git-send-email-tangchen@cn.fujitsu.com> <20121019164045.GE11958@aftab.osrc.amd.com> <5084AB10.7010807@cn.fujitsu.com> <20121022101442.GB8352@liondog.tnic> <50860711.10807@cn.fujitsu.com> <20121023095234.GA22715@liondog.tnic> <50866EBB.2010507@cn.fujitsu.com> <20121023102008.GB24656@liondog.tnic> <508672B9.8010303@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <508672B9.8010303@cn.fujitsu.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1002 Lines: 26 On Tue, Oct 23, 2012 at 06:34:33PM +0800, Miao Xie wrote: > So we add this WARN_ON_ONCE(), it can tell the developers that there > is something wrong in the code if it is triggered. First of all, the WARN_ON_ONCE will fire only once during system lifetime (well, doh, of course) which diminishes debuggability significantly and then, the only other place which deals with CPU_POST_DEAD is kernel/stop_machine.c:cpu_stop_cpu_callback. So, just to sum up and finish this fruitless discussion: cmci_rediscover() correctly ignores the dying cpu and there's *absolutely* no need to warn. If you still think there is, you have to come up with a concrete example and a way for others to reproduce it. Then we can talk. End of story. -- Regards/Gruss, Boris. -- 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/