From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264098AbUG0LSf (ORCPT ); Tue, 27 Jul 2004 07:18:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264261AbUG0LSf (ORCPT ); Tue, 27 Jul 2004 07:18:35 -0400 Received: from [195.23.16.24] ([195.23.16.24]:37350 "EHLO bipbip.comserver-pie.com") by vger.kernel.org with ESMTP id S264098AbUG0LSd (ORCPT ); Tue, 27 Jul 2004 07:18:33 -0400 Subject: Re: Inode question From: Paulo Marques Reply-To: pmarques@grupopie.com To: sankarshana rao Cc: "linux-kernel@vger.kernel.org" In-Reply-To: <20040727012807.96145.qmail@web50901.mail.yahoo.com> References: <20040727012807.96145.qmail@web50901.mail.yahoo.com> Content-Type: text/plain Organization: Grupo PIE Message-Id: <1090927110.11604.7.camel@pmarqueslinux> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6-1mdk Date: Tue, 27 Jul 2004 12:18:30 +0100 Content-Transfer-Encoding: 7bit X-AntiVirus: checked by Vexira MailArmor (version: 2.0.1.16; VAE: 6.26.0.10; VDF: 6.26.0.44; host: bipbip) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2004-07-27 at 02:28, sankarshana rao wrote: > Thx for the inputs.. > I am trying this thing on Mips processor and creating > 500 folders itself takes about 1.6 seconds. That's why > I was wondering if using inodes would make it any > faster.. > pls guide... I really think the name lookup is not your bottleneck. I did some more tests to check where the time to create a dir came from and, as expected, it depends a lot on the filesystem. Using ext3, creating 1000 dirs on my machine (P4 2.8GHz) takes about 100 ms. Using tmpfs, takes only 6 ms. Even a machine 20 times slower would take at most 60ms to do the 500 lookups. Both tests have to do the same lookup on the dentry cache and check for duplicate names, etc. So the real difference is the time *the filesystem* takes to create a dir. You're probably using JFFS2 or something like that, which is almost synchronous (I don't know for sure if it is really synchronous), and writes the updates to flash on every dir creation. I hope this helps, -- Paulo Marques - www.grupopie.com "In a world without walls and fences who needs windows and gates?"