From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261398AbULHXB0 (ORCPT ); Wed, 8 Dec 2004 18:01:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261400AbULHXB0 (ORCPT ); Wed, 8 Dec 2004 18:01:26 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:59826 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S261398AbULHXBX (ORCPT ); Wed, 8 Dec 2004 18:01:23 -0500 Date: Thu, 9 Dec 2004 10:01:18 +1100 From: Greg Banks To: Steve Lord Cc: Linux Kernel Subject: Re: negative dentry_stat.nr_unused causes aggressive dcache pruning Message-ID: <20041208230118.GC4239@sgi.com> References: <41B77D54.4080909@xfs.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41B77D54.4080909@xfs.org> User-Agent: Mutt/1.5.5.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 08, 2004 at 04:16:52PM -0600, Steve Lord wrote: > > I have seen this stat go negative (just from booting up a multi cpu box), > and looking at the code, it is manipulated without locking in a number > of places. I have only seen this in real life on a 2.4 kernel, but 2.6 > also looks vulnerable. On early 2.6.x, a heavy streaming NFS load was a great way to trigger this. I haven't seen it happen since http://linus.bkbits.net:8080/linux-2.5/cset@40b8cf606MV-gl6VpDyWKzzW1jaIJw Greg. -- Greg Banks, R&D Software Engineer, SGI Australian Software Group. I don't speak for SGI.