Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757673AbaFYQX2 (ORCPT ); Wed, 25 Jun 2014 12:23:28 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:38702 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757538AbaFYQXZ (ORCPT ); Wed, 25 Jun 2014 12:23:25 -0400 Message-ID: <53AAF779.8060006@wwwdotorg.org> Date: Wed, 25 Jun 2014 10:23:21 -0600 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Peter Zijlstra , "Srivatsa S. Bhat" CC: Frederic Weisbecker , LKML , Andrew Morton , Eric Dumazet , Ingo Molnar , Kevin Hilman , "Paul E. McKenney" , Thomas Gleixner , Viresh Kumar , "linux-next@vger.kernel.org" Subject: Re: [PATCH 2/6] irq_work: Implement remote queueing References: <1402413309-3415-1-git-send-email-fweisbec@gmail.com> <1402413309-3415-3-git-send-email-fweisbec@gmail.com> <53A9E0A5.5040402@wwwdotorg.org> <20140625051234.GD6758@twins.programming.kicks-ass.net> <20140625051721.GG3588@twins.programming.kicks-ass.net> <53AA6E11.1000404@linux.vnet.ibm.com> <20140625093657.GN19860@laptop.programming.kicks-ass.net> <20140625093944.GV16155@laptop.programming.kicks-ass.net> <53AA9B68.4050104@linux.vnet.ibm.com> <53AA9C43.3020903@linux.vnet.ibm.com> <20140625101915.GO19860@laptop.programming.kicks-ass.net> In-Reply-To: <20140625101915.GO19860@laptop.programming.kicks-ass.net> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/25/2014 04:19 AM, Peter Zijlstra wrote: > On Wed, Jun 25, 2014 at 03:24:11PM +0530, Srivatsa S. Bhat wrote: >> Wait, that was a stupid idea. hotplug_cfd() already invokes irq_work_run >> indirectly via flush_smp_call_function_queue(). So irq_work_cpu_notify() >> doesn't need to invoke it again, AFAIU. So perhaps we can get rid of >> irq_work_cpu_notify() altogether? > > Just so... > > getting up at 6am and sitting in an airport terminal doesn't seem to > agree with me; any more silly fail here? > > --- > Subject: irq_work: Remove BUG_ON in irq_work_run() > From: Peter Zijlstra > Date: Wed Jun 25 07:13:07 CEST 2014 > > Because of a collision with 8d056c48e486 ("CPU hotplug, smp: flush any > pending IPI callbacks before CPU offline"), which ends up calling > hotplug_cfd()->flush_smp_call_function_queue()->irq_work_run(), which > is not from IRQ context. > > And since that already calls irq_work_run() from the hotplug path, > remove our entire hotplug handling. Tested-by: Stephen Warren [with the s/static// already mentioned in this thread, obviously:-)] -- 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/