From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753690AbaCRIv4 (ORCPT ); Tue, 18 Mar 2014 04:51:56 -0400 Received: from merlin.infradead.org ([205.233.59.134]:53964 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750798AbaCRIvx (ORCPT ); Tue, 18 Mar 2014 04:51:53 -0400 Date: Tue, 18 Mar 2014 09:51:18 +0100 From: Peter Zijlstra To: "Paul E. McKenney" Cc: mingo@elte.hu, josh@joshtriplett.org, laijs@cn.fujitsu.com, linux-kernel@vger.kernel.org Subject: Re: cond_resched() and RCU CPU stall warnings Message-ID: <20140318085118.GO25546@laptop.programming.kicks-ass.net> References: <20140316015914.GA22102@linux.vnet.ibm.com> <20140317101300.GA27965@twins.programming.kicks-ass.net> <20140317165806.GG21124@linux.vnet.ibm.com> <20140317171434.GJ25546@laptop.programming.kicks-ass.net> <20140318021706.GE4420@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140318021706.GE4420@linux.vnet.ibm.com> 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 Mon, Mar 17, 2014 at 07:17:06PM -0700, Paul E. McKenney wrote: > On Mon, Mar 17, 2014 at 06:14:34PM +0100, Peter Zijlstra wrote: > > On Mon, Mar 17, 2014 at 09:58:07AM -0700, Paul E. McKenney wrote: > > > @@ -4111,6 +4115,7 @@ int __sched __cond_resched_softirq(void) > > > { > > > BUG_ON(!in_softirq()); > > > > > > + rcu_cond_resched(); > > > > Don't you have to enable BHs before doing that? And if not; that needs a > > comment for sure! :-) > > No need to enable BHs, just RCU marking quiescent states. But yes, > the name does look a bit scary in that context, doesn't it? Added > a comment, please see below for updated patch. The below seemed like an unrelated patch entirely :-) > ------------------------------------------------------------------------ > > torture: Better summary diagnostics for build failures > > The reaction of kvm-recheck.sh is obscure at best, and easy to miss > completely. This commit therefore prints "BUG: Build failed" in the > summary at the end of a run. > > Signed-off-by: Paul E. McKenney