Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264110AbTE0UMI (ORCPT ); Tue, 27 May 2003 16:12:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264106AbTE0UMH (ORCPT ); Tue, 27 May 2003 16:12:07 -0400 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:64666 "EHLO dualathlon.random") by vger.kernel.org with ESMTP id S264057AbTE0UMG (ORCPT ); Tue, 27 May 2003 16:12:06 -0400 Date: Tue, 27 May 2003 22:25:20 +0200 From: Andrea Arcangeli To: Marcelo Tosatti Cc: Marc-Christian Petersen , linux-kernel@vger.kernel.org, Carl-Daniel Hailfinger , manish , Christian Klose , William Lee Irwin III Subject: Re: 2.4.20: Proccess stuck in __lock_page ... Message-ID: <20030527202520.GN3767@dualathlon.random> References: <3ED2DE86.2070406@storadinc.com> <200305271952.34843.m.c.p@wolk-project.de> <200305272004.02376.m.c.p@wolk-project.de> <20030527182547.GG3767@dualathlon.random> <20030527200339.GI3767@dualathlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4i X-GPG-Key: 1024D/68B9CB43 X-PGP-Key: 1024R/CB4660B9 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1988 Lines: 49 On Tue, May 27, 2003 at 05:08:38PM -0300, Marcelo Tosatti wrote: > > > On Tue, 27 May 2003, Andrea Arcangeli wrote: > > > > It seems your "fix-pausing" patch is fixing a potential wakeup > > > miss, right? (I looked quickly throught it). Could you explain me the > > > > yes, not just one but multiple of them, all similar. lots of boxes were > > hanging in a weird manner until I found and fixed this glitch. > > > > > problem its trying to fix and how? > > > > I'm attaching the old email, it should have all the explanataions. > > > > but don't use that old patch (that was the first revision and it missed > > one last race in wait_for_request noticed by Chris or Andrew [or > > both?]), use this one instead (seems just the second revision, should be > > that one plus that last race fix): > > > > http://www.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.21rc2aa1/9980_fix-pausing-2 > > I wonder if the additional wakeups result in performance degradation (not > that it matters much in case there is no other way to fix the problem). in theory yes. > > But anyway I would like to have some numbers with/without the patch. > > Do you have them ? Hmm, in bigbox.html we should find the difference of the timings before/after, and I recall it wasn't measurable. I can search for it on Thu if you want the exact numbers. However the last numbers from Randy showed my tree going faster than 2.5 with bonnie and tiotest so I think we don't need to worry and I would probably not fix it in a different way in 2.4 even if it would mean a 1% degradation. When it was shipped there was no time to measure any degradation but the problem it fix is so severe that we never had any doubt if to include it or not ;). Andrea - 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/