From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36404) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YNMua-0006fk-Px for qemu-devel@nongnu.org; Mon, 16 Feb 2015 09:44:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YNMuZ-00046p-Iv for qemu-devel@nongnu.org; Mon, 16 Feb 2015 09:44:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39492) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YNMuZ-00046i-BN for qemu-devel@nongnu.org; Mon, 16 Feb 2015 09:44:35 -0500 Message-ID: <54E2024F.9040501@redhat.com> Date: Mon, 16 Feb 2015 15:44:31 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <54E0E974.4010301@profihost.ag> <54E1E188.4050407@redhat.com> <54E20226.8090103@profihost.ag> In-Reply-To: <54E20226.8090103@profihost.ag> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] slow speed for virtio-scsi since qemu 2.2 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Priebe - Profihost AG , qemu-devel On 16/02/2015 15:43, Stefan Priebe - Profihost AG wrote: > Hi, > > Am 16.02.2015 um 13:24 schrieb Paolo Bonzini: >> >> >> On 15/02/2015 19:46, Stefan Priebe wrote: >>> >>> while i get a constant random 4k i/o write speed of 20.000 iops with >>> qemu 2.1.0 or 2.1.3. I get jumping speeds with qemu 2.2 (jumping between >>> 500 iops and 15.000 iop/s). >>> >>> If i use virtio instead of virtio-scsi speed is the same between 2.2 and >>> 2.1. >> >> http://wiki.qemu.org/Contribute/ReportABug >> >> What is your command line? > > Could it be that this is a results of compiling qemu with --enable-debug > to get debugging symbols? Yes. Paolo