Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262247AbTERWpl (ORCPT ); Sun, 18 May 2003 18:45:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262249AbTERWpl (ORCPT ); Sun, 18 May 2003 18:45:41 -0400 Received: from h68-147-142-75.cg.shawcable.net ([68.147.142.75]:59630 "EHLO schatzie.adilger.int") by vger.kernel.org with ESMTP id S262247AbTERWpj (ORCPT ); Sun, 18 May 2003 18:45:39 -0400 Date: Sun, 18 May 2003 16:57:18 -0600 From: Andreas Dilger To: Alex Tomas Cc: linux-kernel@vger.kernel.org, ext2-devel@lists.sourceforge.net Subject: Re: [Ext2-devel] [RFC] fast EA for ext3 Message-ID: <20030518165718.B11651@schatzie.adilger.int> Mail-Followup-To: Alex Tomas , linux-kernel@vger.kernel.org, ext2-devel@lists.sourceforge.net References: <87n0hkmbiw.fsf@gw.home.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <87n0hkmbiw.fsf@gw.home.net>; from bzzz@tmi.comex.ru on Sun, May 18, 2003 at 05:04:39PM +0000 X-GPG-Key: 1024D/0D35BED6 X-GPG-Fingerprint: 7A37 5D79 BF1B CECA D44F 8A29 A488 39F5 0D35 BED6 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1416 Lines: 34 On May 18, 2003 17:04 +0000, Alex Tomas wrote: > this patch implements possibility to store EA into inode body > which may be larger 128 bytes in 2.5 kernel. What Alex didn't mention was the reason why we developed this patch in the first place - speed. Storing EAs in external blocks is slow, and if you have a lot of inodes with external EAs it is fatal, as the EA blocks consume so much RAM that they force all of the inode/directory data out of cache. Some benchmarks (from Alex): > environment for old EA: just mkfs'ed EXT3, inode size 128, 33000 files > environment for fast EA: just mkfs'ed EXT3, inode size 256, 33000 files > > old EA fast EA > add attributes 2m35.241s 1m4.151s (+142%) > dump attributes 0m28.716s 0m13.466s (+113%) > change attributes 2m42.108s 1m4.413s (+153%) > remove attributes 1m15.373s 1m3.909s (+19%) Some minor improvements could be made, such as not storing user EAs inside the inode if there are system EAs that could be stored there. Cheers, Andreas -- Andreas Dilger http://sourceforge.net/projects/ext2resize/ http://www-mddsp.enel.ucalgary.ca/People/adilger/ - 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/