Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760244AbXIUQRy (ORCPT ); Fri, 21 Sep 2007 12:17:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755538AbXIUQRs (ORCPT ); Fri, 21 Sep 2007 12:17:48 -0400 Received: from mx1.redhat.com ([66.187.233.31]:57246 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752710AbXIUQRr (ORCPT ); Fri, 21 Sep 2007 12:17:47 -0400 Message-ID: <46F3EE62.9010907@redhat.com> Date: Fri, 21 Sep 2007 12:16:34 -0400 From: Chuck Ebbert Organization: Red Hat User-Agent: Thunderbird 1.5.0.12 (X11/20070719) MIME-Version: 1.0 To: Hugh Dickins CC: Andy Whitcroft , Andrew Morton , Matthias Hensler , linux-kernel , Thomas Gleixner , richard kennedy , Peter Zijlstra Subject: Re: Processes spinning forever, apparently in lock_timer_base()? References: <46B10BB7.60900@redhat.com> <20070803113407.0b04d44e.akpm@linux-foundation.org> <20070804084426.GA20464@kobayashi-maru.wspse.de> <20070809095943.GA7763@kobayashi-maru.wspse.de> <20070809095534.25ae1c42.akpm@linux-foundation.org> <46F2E103.8000907@redhat.com> <20070920142927.d87ab5af.akpm@linux-foundation.org> <20070921093914.GB4750@shadowen.org> In-Reply-To: Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1412 Lines: 29 On 09/21/2007 11:58 AM, Hugh Dickins wrote: > Looking at the 2.6.18-2.6.23 code, I'm uncertain what to try instead. > There is a refresh_vm_stats function which we could call (then retest > the break condition) just before resorting to congestion_wait. But > the big NUMA people might get very upset with me calling that too > often: causing a thundering herd of bouncing cachelines which that > was all designed to avoid. And it's not obvious to me what condition > to test for dirty_thresh "too low". > > I believe Peter gave all this quite a lot of thought when he was > making the rc6-mm1 changes, and I'd rather defer to him for a > suggestion of what best to do in earlier releases. Or maybe he'll > just point out how this couldn't have been a problem before. > > Or there is is Richard's patch, which I haven't considered, but > Andrew was not quite satisfied with it - partly because he'd like > to understand how the situation could come about first, perhaps > we have now got an explanation. > My patch is just Richard's with the added requirement that we loop some minimum number of times before exiting balance_dirty_pages() with unfinished work. - 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/