From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937991AbZAPWc0 (ORCPT ); Fri, 16 Jan 2009 17:32:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757134AbZAPWcN (ORCPT ); Fri, 16 Jan 2009 17:32:13 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:36665 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751753AbZAPWcL (ORCPT ); Fri, 16 Jan 2009 17:32:11 -0500 Date: Fri, 16 Jan 2009 23:32:02 +0100 From: Ingo Molnar To: Mike Travis Cc: Rusty Russell , LKML Subject: Re: [PULL}: latest tip/cpus4096 changes Message-ID: <20090116223202.GC3899@elte.hu> References: <49704DF6.8040205@sgi.com> <20090116142514.GA1269@elte.hu> <4970CBD7.4070006@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4970CBD7.4070006@sgi.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -0.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-0.5 required=5.9 tests=BAYES_20 autolearn=no SpamAssassin version=3.2.3 -0.5 BAYES_20 BODY: Bayesian spam probability is 5 to 20% [score: 0.1787] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Mike Travis wrote: > Ingo Molnar wrote: > > * Mike Travis wrote: > > > >> commit b758cdbee5da0b8fb7e34a68651e6ccc5310b48a > >> Author: Rusty Russell > >> Date: Thu Jan 15 16:29:16 2009 -0800 > >> > >> work_on_cpu: Use our own workqueue. > >> > >> Impact: remove potential circular lock dependency with generic kevent workqueue > >> > >> Annoyingly, some places we want to use work_on_cpu are already in > >> workqueues. As per Ingo's suggestion, we create a different workqueue > >> for work_on_cpu. > > > > btw., that's a nice fix - were you able to reproduce any of the lockdep > > asserts that i got in testing, and did those go away with this patch? > > > > If yes then that's nice and makes work_on_cpu() a lot more usable IMO. > > > > If not then that should generally be declared in the pull request: > > "beware, different approach than before but might still trigger lockdep > > warnings" > > > > Ingo > > Hi, > > I've been trying all sorts of overlapping testing and I've not gotten the > lockdep warnings any more. (I do occasionally get that debug object warning > that I mentioned to Thomas, though that comes and goes irregardless of any > patches.) [...] That hpet warning is fixed in tip/timers/urgent [which you wont have if you try pure tip/cpus4096]. > [...] The two fixes that Rusty did (lose the get_online_cpus() and use > a separate work queue) seems to have relieved work_on_cpu of it's > primary problems, and I've not found any new ones to replace them yet. > ;-) > > So I'll "un-push" the entire patchset, and then re-push the x86 only > ones, and send the others to their respective maintainers after fixing > the problems you mentioned. (Posting patches to the list was way more > fun, and less "committable". ;-) Sounds good. Ingo