Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262261AbTFIW4c (ORCPT ); Mon, 9 Jun 2003 18:56:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262271AbTFIW4c (ORCPT ); Mon, 9 Jun 2003 18:56:32 -0400 Received: from e32.co.us.ibm.com ([32.97.110.130]:16092 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S262261AbTFIW4Z (ORCPT ); Mon, 9 Jun 2003 18:56:25 -0400 Message-ID: <3EE5190D.3070401@austin.ibm.com> Date: Mon, 09 Jun 2003 18:32:29 -0500 From: Steven Pratt User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.2) Gecko/20021120 Netscape/7.01 X-Accept-Language: en-us, en MIME-Version: 1.0 To: linux-kernel Subject: 2.5.70-mm2 causes performance drop of random read O_DIRECT Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1299 Lines: 27 Starting in 2.5.70-mm2 and continuing in the mm tree, there is a significant degrade in random read for block devices using O_DIRECT. The drop occurs for all block sizes and ranges from 30%-40. CPU usage is also lower although it may already be so low as to be irrelavent. tolerance = 0.00 + 3.00% of 2.5.70-mm1 2.5.70-mm1 2.5.70-mm2 Blocksize KBs/sec KBs/sec %diff diff tolerance ---------- ------------ ------------ -------- ------------ ------------ 4096 1567 924 -41.03 -643.00 47.01 * 8192 3057 1815 -40.63 -1242.00 91.71 * 16384 5745 3509 -38.92 -2236.00 172.35 * 65536 17357 11283 -34.99 -6074.00 520.71 * 262144 37537 27302 -27.27 -10235.00 1126.11 * Full results can be found at: http://www-124.ibm.com/developerworks/oss/linuxperf/regression/2.5.70-mm2/2.5.70-mm1-vs-2.5.70-mm2/ Steve - 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/