From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754509AbYJCPNX (ORCPT ); Fri, 3 Oct 2008 11:13:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752807AbYJCPNL (ORCPT ); Fri, 3 Oct 2008 11:13:11 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:49578 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752935AbYJCPNK (ORCPT ); Fri, 3 Oct 2008 11:13:10 -0400 Date: Fri, 3 Oct 2008 08:13:06 -0700 From: "Paul E. McKenney" To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, mathieu.desnoyers@polymtl.ca, akpm@linux-foundation.org, laijs@cn.fujitsu.com, manfred@colorfullife.com, dipankar@in.ibm.com, niv@us.ibm.com, dvhltc@us.ibm.com, josht@linux.vnet.ibm.com, ltt-dev@lists.casi.polymtl.ca Subject: Re: [PATCH tip/master] RCU-based detection of stalled CPUs for Classic RCU Message-ID: <20081003151306.GB6246@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20081002003628.GA7877@linux.vnet.ibm.com> <20081002080726.GB17695@elte.hu> <20081002140507.GB6729@linux.vnet.ibm.com> <20081002151046.GB2473@Krystal> <20081002174318.GB7324@linux.vnet.ibm.com> <20081002185115.GA11047@Krystal> <20081002225537.GA6706@linux.vnet.ibm.com> <20081002230639.GA7522@linux.vnet.ibm.com> <20081003083947.GB7636@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081003083947.GB7636@elte.hu> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 03, 2008 at 10:39:47AM +0200, Ingo Molnar wrote: > > * Paul E. McKenney wrote: > > > Hello! > > > > This patch adds stalled-CPU detection to Classic RCU. This capability > > is enabled by a new config variable CONFIG_RCU_CPU_STALL_DETECTOR, > > which defaults disabled. This is a debugging feature to detect > > infinite loops in kernel code, not something that non-kernel-hackers > > would be expected to care about. This feature can detect looping CPUs > > in !PREEMPT builds and looping CPUs with preemption disabled in > > PREEMPT builds. This is essentially a port of this functionality from > > the treercu patch, replacing the stall debug patch that is already in > > tip/core/rcu (commit 67182ae1c4). > > > > The changes from the patch in tip/core/rcu include making the config > > variable name match that in treercu, changing from seconds to jiffies > > to avoid spurious warnings, and printing a boot message when this > > feature is enabled. > > > > Signed-off-by: Paul E. McKenney > > applied to tip/core/rcu, thanks Paul! > > i tidied up two tiny details noticed by scripts/checkpatch.pl: > > > +#define RCU_SECONDS_TILL_STALL_CHECK 3 * HZ /* for rcp->jiffies_stall */ > > +#define RCU_SECONDS_TILL_STALL_RECHECK 30 * HZ /* for rcp->jiffies_stall */ > > adding paranthesis around the expression. > > > + if (cpu_isset(smp_processor_id(), rcp->cpumask) && delta >= 0) { > > + > > and have removed the two tailing tabs from this line. checkpatch.pl... I have heard of it! :-) Thanx, Paul