From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753118AbbDBMo3 (ORCPT ); Thu, 2 Apr 2015 08:44:29 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:35849 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752415AbbDBMo2 (ORCPT ); Thu, 2 Apr 2015 08:44:28 -0400 Message-ID: <551D39A2.8020009@linux.vnet.ibm.com> Date: Thu, 02 Apr 2015 18:14:18 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Ingo Molnar , Peter Zijlstra CC: nicolas.pitre@linaro.org, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, tglx@linutronix.de, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH V2] clockevents: Fix cpu down race for hrtimer based broadcasting References: <20150330092410.24979.59887.stgit@preeti.in.ibm.com> <20150402104226.GB21105@gmail.com> <20150402120256.GV23123@twins.programming.kicks-ass.net> <20150402121247.GA18104@gmail.com> In-Reply-To: <20150402121247.GA18104@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15040212-0017-0000-0000-000009CC177B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/02/2015 05:42 PM, Ingo Molnar wrote: > > * Peter Zijlstra wrote: > >> On Thu, Apr 02, 2015 at 12:42:27PM +0200, Ingo Molnar wrote: >>> So why not use a suitable CPU_DOWN* notifier for this, instead of open >>> coding it all into a random place in the hotplug machinery? >> >> Because notifiers are crap? ;-) [...] > > No doubt - but I didn't feel this poorly named random call into the > hotplug code, with no comments was any better. > >> [...] Its entirely impossible to figure out what's happening to core >> code in hotplug. You need to go chase down and random order notifier >> things. >> >> I'm planning on taking out many of the core hotplug notifiers and >> hard coding their callbacks into the hotplug code. > > That's very welcome news - but please also lets put in place a proper > namespace for all these callbacks, to make them easy to find and > change: hotplug_cpu__*() or so, which in this case would turn into > hotplug_cpu__tick_pull() or so? > >> That way at least its clear wtf happens when. > > Okay. I'll resurrect the fix with a hotplug_cpu__tick_pull() name - > agreed? Sounds good to me. This needs to be marked to stable also. Regards Preeti U Murthy