Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261867AbUD1ULw (ORCPT ); Wed, 28 Apr 2004 16:11:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261862AbUD1UKM (ORCPT ); Wed, 28 Apr 2004 16:10:12 -0400 Received: from fw.osdl.org ([65.172.181.6]:52202 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S261867AbUD1Ts2 (ORCPT ); Wed, 28 Apr 2004 15:48:28 -0400 Date: Wed, 28 Apr 2004 12:48:09 -0700 From: Andrew Morton To: busterbcook@yahoo.com Cc: linux-kernel@vger.kernel.org Subject: Re: pdflush eating a lot of CPU on heavy NFS I/O Message-Id: <20040428124809.418e005d.akpm@osdl.org> In-Reply-To: References: <20040427230203.1e4693ac.akpm@osdl.org> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-redhat-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 Content-Length: 2207 Lines: 59 Brent Cook wrote: > > On Tue, 27 Apr 2004, Andrew Morton wrote: > > > Brent Cook wrote: > > > > > > Running any kernel from the 2.6.6-rc* series (and a few previous > > > -mm*'s), > > > > It's a shame this wasn't reported earlier. > > Since it was a pretty big deal on my system, I just assumed it was for > other people's too, and that someone else would have reported it by > now. I only got concerned when it persisted between rc's. I think three people have reported it now. > > > the pdflush process starts using near 100% CPU indefinitely after > > > a few minutes of initial NFS traffic, as far as I can tell. > > > > Please confirm that the problem is observed on the NFS client and not the > > NFS server? I'll assume the client. > > Yes, both affected machines had the issue when connecting as a client to a > 2.4.25-based NFS server. > > > What other filesystems are in use on the client? > > One uses Reiser on /, the other uses ext3 on /. Here is the mount table > for one machine: Both machines are exhibiting the problem? > About 10 minutes into the process, pdflush starts taking over: > > PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND > 7 root 25 0 0 0 0 RW 34.4 0.0 3:05 0 pdflush > 17856 busterb 25 0 69400 65M 5140 R 34.4 26.1 0:31 0 cc1plus > 19466 busterb 25 0 43732 39M 5140 R 26.3 15.5 0:03 0 cc1plus > ... > The network light will flash continually on each machine once pdflush > gets into this state, which makes me think NFS. Each machine has > 512-256 MB of ram and a single CPU. ok.. I spent a couple of hours yesterday trying to get this to happen. No joy. Can't make it happen with your .config either. I'll set up a 2.4.25 server later on. What version of gcc are you using? Could you please capture the contents of /proc/meminfo and /proc/vmstats when it's happening? Thanks. - 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/