From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755964AbYKISco (ORCPT ); Sun, 9 Nov 2008 13:32:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755564AbYKIScg (ORCPT ); Sun, 9 Nov 2008 13:32:36 -0500 Received: from voyager.telenet.dn.ua ([195.39.211.35]:46548 "EHLO voyager.telenet.dn.ua" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755548AbYKIScg (ORCPT ); Sun, 9 Nov 2008 13:32:36 -0500 Message-ID: <49172CA8.5060309@telenet.dn.ua> Date: Sun, 09 Nov 2008 20:32:08 +0200 From: "Vitaly V. Bursov" User-Agent: Thunderbird 2.0.0.17 (X11/20081011) MIME-Version: 1.0 To: Alexey Dobriyan CC: linux-kernel@vger.kernel.org, devel@openvz.org Subject: Re: Slow file transfer speeds with CFQ IO scheduler in some cases References: <4917263D.2090904@telenet.dn.ua> <20081109183043.GA4530@x200.localdomain> In-Reply-To: <20081109183043.GA4530@x200.localdomain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexey Dobriyan wrote: > On Sun, Nov 09, 2008 at 08:04:45PM +0200, Vitaly V. Bursov wrote: >> I'm building small server system with openvz kernel and have ran into >> some IO performance problems. Reading a single file via NFS delivers >> around 9 MB/s over gigabit network, but while reading, say, 2 different >> or same file 2 times at the same time I get >60MB/s. > > openvz kernels have very changed CFQ and, IIRC, this one-reader problem is > fixed somewhere. Ask devel@openvz.org. That's why I've checked vanilla kernel also. It performs somewhat better, but definitely shares same issues...