From: Alex Tomas Subject: Re: More testing: 4x parallel 2G writes, sequential reads Date: Thu, 08 Nov 2007 02:17:55 +0300 Message-ID: <473247A3.5020800@gmail.com> References: <47323F73.5080708@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=ISO-8859-1 Content-Transfer-Encoding: 7BIT Cc: ext4 development To: Eric Sandeen Return-path: Received: from gmp-eb-mail-2.sun.com ([192.18.6.24]:55052 "EHLO gmp-eb-mail-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755066AbXKGXSK (ORCPT ); Wed, 7 Nov 2007 18:18:10 -0500 Received: from fe-emea-09.sun.com (gmp-eb-lb-2-fe2.eu.sun.com [192.18.6.11]) by gmp-eb-mail-2.sun.com (8.13.7+Sun/8.12.9) with ESMTP id lA7NI8Hg014437 for ; Wed, 7 Nov 2007 23:18:08 GMT Received: from conversion-daemon.fe-emea-09.sun.com by fe-emea-09.sun.com (Sun Java System Messaging Server 6.2-8.04 (built Feb 28 2007)) id <0JR500G01SJA3Q00@fe-emea-09.sun.com> (original mail from bzzz.tomas@gmail.com) for linux-ext4@vger.kernel.org; Wed, 07 Nov 2007 23:18:08 +0000 (GMT) In-reply-to: <47323F73.5080708@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hi, could you try to larger preallocation? like 512/1024/2048 blocks, please? thanks, Alex Eric Sandeen wrote: > I tried ext4 vs. xfs doing 4 parallel 2G IO writes in 1M units to 4 > different subdirectories of the root of the filesystem: > > http://people.redhat.com/esandeen/seekwatcher/ext4_4_threads.png > http://people.redhat.com/esandeen/seekwatcher/xfs_4_threads.png > http://people.redhat.com/esandeen/seekwatcher/ext4_xfs_4_threads.png > > and then read them back sequentially: > > http://people.redhat.com/esandeen/seekwatcher/ext4_4_threads_read.png > http://people.redhat.com/esandeen/seekwatcher/xfs_4_threads_read.png > http://people.redhat.com/esandeen/seekwatcher/ext4_xfs_4_read_threads.png > > At the end of the write, ext4 had on the order of 400 extents/file, xfs > had on the order of 30 extents/file. It's clear especially from the > read graph that ext4 is interleaving the 4 files, in about 5M chunks on > average. Throughput seems comparable between ext4 & xfs nonetheless. > > Again this was on a decent HW raid so seek penalties are probably not > too bad. > > -Eric > - > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >