From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: pm-hibernate : possible circular locking dependency detected Date: Wed, 8 Apr 2009 14:26:13 +0200 Message-ID: <20090408122613.GD18581@elte.hu> References: <200904071356.29914.rusty@rustcorp.com.au> <1239087953.798.5513.camel@twins> <200904081247.08712.rusty@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <200904081247.08712.rusty@rustcorp.com.au> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Rusty Russell , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Steven Rostedt Cc: Peter Zijlstra , Linux Kernel List , Andrew Morton , Linux-pm mailing list List-Id: linux-pm@vger.kernel.org * Rusty Russell wrote: > On Tuesday 07 April 2009 16:35:53 Peter Zijlstra wrote: > > On Tue, 2009-04-07 at 13:56 +0930, Rusty Russell wrote: > > > Looks like this will be fixed by Andrew's work-on-cpu-in-own-thread > > > patch which I just put out the pull request for. > > > > Would it make sense to teach it about a short-circuit like: > > > > work_on_cpu() { > > > > if (cpumask_weight(current->cpus_allowed) == 1 && > > smp_processor_id() == cpu) > > return do_work_right_here(); > > Does that happen much? I guess put a counter in and see? a temporary tracepoint or trace_printk() for the workqueue tracer would also tell this, without any long-term overhead (it will be easy to remove it). Ingo