Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755445AbaFYJjx (ORCPT ); Wed, 25 Jun 2014 05:39:53 -0400 Received: from casper.infradead.org ([85.118.1.10]:57395 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751483AbaFYJjv (ORCPT ); Wed, 25 Jun 2014 05:39:51 -0400 Date: Wed, 25 Jun 2014 11:39:44 +0200 From: Peter Zijlstra To: "Srivatsa S. Bhat" Cc: Stephen Warren , 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 Message-ID: <20140625093944.GV16155@laptop.programming.kicks-ass.net> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140625093657.GN19860@laptop.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 25, 2014 at 11:36:57AM +0200, Peter Zijlstra wrote: > On Wed, Jun 25, 2014 at 12:07:05PM +0530, Srivatsa S. Bhat wrote: > > I don't think irqs_disabled() is the problematic condition, since > > hotplug_cfg() invokes irq_work_run() from CPU_DYING context (which has > > irqs disabled). I guess you meant to remove the in_irq() check inside > > irq_work_run() instead? > > Yes, clearly I should not get up at 6am.. :-) Let me go do a new one. --- 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. Cc: Frederic Weisbecker Reported-by: Stephen Warren Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-busatzs2gvz4v62258agipuf@git.kernel.org --- kernel/irq_work.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) Index: linux-2.6/kernel/irq_work.c =================================================================== --- linux-2.6.orig/kernel/irq_work.c +++ linux-2.6/kernel/irq_work.c @@ -160,21 +160,11 @@ static void irq_work_run_list(struct lli } } -static void __irq_work_run(void) +static void irq_work_run(void) { irq_work_run_list(&__get_cpu_var(raised_list)); irq_work_run_list(&__get_cpu_var(lazy_list)); } - -/* - * Run the irq_work entries on this cpu. Requires to be ran from hardirq - * context with local IRQs disabled. - */ -void irq_work_run(void) -{ - BUG_ON(!in_irq()); - __irq_work_run(); -} EXPORT_SYMBOL_GPL(irq_work_run); /* -- 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/