From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1424160AbWKIRa0 (ORCPT ); Thu, 9 Nov 2006 12:30:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1424162AbWKIRa0 (ORCPT ); Thu, 9 Nov 2006 12:30:26 -0500 Received: from nf-out-0910.google.com ([64.233.182.189]:17930 "EHLO nf-out-0910.google.com") by vger.kernel.org with ESMTP id S1424160AbWKIRaZ (ORCPT ); Thu, 9 Nov 2006 12:30:25 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=Xm8bvHvkKllSVWSkn4Us/RhIrrLbERQKxScxNS/sK3jL7T8WSAGdhThTTDyhjFcVDjnb/zs3tEmQWfVCXnhO7rPQQaylv4kkloVxQDzE8LV1CI2f3mFRPq4tDuDmyQS9vqWQh9FZZ04WJVyPEuvMWxU/Byzi9Cd4PJwEspL1htU= Message-ID: Date: Thu, 9 Nov 2006 20:30:23 +0300 From: "Igor A. Valcov" To: linux-kernel Subject: XFS filesystem performance drop in kernels 2.6.16+ MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, For one of our projects we have a test program that measures file system performance by writing up to 1000 files simultaneously. After installing kernel v2.6.16 we noticed that XFS performance dropped by a factor of 5 (tests that took around 4 minutes on kernel 2.6.15 now take around 20 minutes to complete). We then checked all kernels starting from 2.6.16 up to 2.6.19-rc5 with the same unpleasant result. The funny thing about all this is that we chose XFS for that particular project specifically because it was about 5 times faster with the tests than the other file systems. Now they all take about the same time. I also noticed that I/O barriers were introduced in v2.6.16 and thought they may be the cause, but mounting the file system with 'nobarrier' doesn't seem to affect the performance in any way. Any thoughts on the matter are appreciated. Thanks in advance, -- Igor A. Valcov