Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751798AbWHUBbo (ORCPT ); Sun, 20 Aug 2006 21:31:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751800AbWHUBbo (ORCPT ); Sun, 20 Aug 2006 21:31:44 -0400 Received: from mx1.suse.de ([195.135.220.2]:18598 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751798AbWHUBbn (ORCPT ); Sun, 20 Aug 2006 21:31:43 -0400 From: Neil Brown To: "Miquel van Smoorenburg" Date: Mon, 21 Aug 2006 11:31:20 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17641.3304.948174.971955@cse.unsw.edu.au> Cc: linux-kernel@vger.kernel.org, Andrzej Szymanski Subject: Re: Strange write starvation on 2.6.17 (and other) kernels In-Reply-To: message from Miquel van Smoorenburg on Thursday August 17 References: <44E0A69C.5030103@agh.edu.pl> X-Mailer: VM 7.19 under Emacs 21.4.1 X-face: [Gw_3E*Gng}4rRrKRYotwlE?.2|**#s9D In article <44E0A69C.5030103@agh.edu.pl>, > Andrzej Szymanski wrote: > >I've encountered a strange problem - if an application is sequentially > >writing a large file on a busy machine, a single write() of 64KB may > >take even 30 seconds. But if I do fsync() after each write() the maximum > >time of write()+fsync() is about 0.5 second (the overall performance is, > >of course, degraded). > > I'm seeing something similar. Can you report the contents of /proc/meminfo before, during, and after the long pause? I'm particularly interested in MemTotal, Dirty, and Writeback, but the others are of interest too. Thanks, NeilBrown - 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/