From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271771AbTGRQla (ORCPT ); Fri, 18 Jul 2003 12:41:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270255AbTGRQjv (ORCPT ); Fri, 18 Jul 2003 12:39:51 -0400 Received: from fw.osdl.org ([65.172.181.6]:45264 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S267517AbTGRQiP (ORCPT ); Fri, 18 Jul 2003 12:38:15 -0400 Date: Fri, 18 Jul 2003 09:45:42 -0700 From: Andrew Morton To: Peter Osterlund Cc: pavel@ucw.cz, linux-kernel@vger.kernel.org Subject: Re: Software suspend testing in 2.6.0-test1 Message-Id: <20030718094542.07b2685a.akpm@osdl.org> In-Reply-To: References: <20030717200039.GA227@elf.ucw.cz> <20030717130906.0717b30d.akpm@osdl.org> <20030718032433.4b6b9281.akpm@osdl.org> <20030718152205.GA407@elf.ucw.cz> X-Mailer: Sylpheed version 0.9.0pre1 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 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 Peter Osterlund wrote: > > I tried the patch below, but it didn't work. Nothing (or very little) > was swapped out to disk. I also tried using GFP_KERNEL, but that > seemed to cause a deadlock. (Maybe it would have gone OOM if I had > waited long enough). I think the problem is that pdflush and friends > are already frozen when this code runs. Oh, we shouldn't be doing this sort of thing when the kernel threads are refrigerated. We do need kswapd services for the trick you tried. And all flavours of ext3_writepage() can block on kjournald activity, so if kjournald is refrigerated during the memory shrink the machine can deadlock. It would be much better to freeze kernel threads _after_ doing the big memory shrink.