From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Wed, 14 May 2008 21:56:38 -0700 (PDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m4F4uFhC012010 for ; Wed, 14 May 2008 21:56:17 -0700 Date: Thu, 15 May 2008 00:57:00 -0400 From: Christoph Hellwig Subject: Re: [PATCH 3/4] XFS: Return case-insensitive match for dentry cache Message-ID: <20080515045700.GA4328@infradead.org> References: <20080513075749.477238845@chook.melbourne.sgi.com> <20080513080152.911303131@chook.melbourne.sgi.com> <20080513085724.GC21919@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Barry Naujok Cc: Christoph Hellwig , xfs@oss.sgi.com, linux-fsdevel@vger.kernel.org, aia21@cantab.net On Wed, May 14, 2008 at 05:55:45PM +1000, Barry Naujok wrote: > Not quite sure if this is the right test, but I did 1000 creates on > a brand new filesystem with and without ci on my SATA drive, both > sustained almost 600 creates per second. > > I believe creates would be the worst case scenario for not adding > negative dentries? No, negative dentries shouldn't have any effect on that. negative entries help to optimize away lookups. E.g. thing of the PATH variable and say your shell is not in the first directory listed there. Having a negative dentry for it means that you don't have to do a lookup in the first directories everytime someone wants to use the shell.