From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54496) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S5EwO-0002Oi-Ro for qemu-devel@nongnu.org; Wed, 07 Mar 2012 06:21:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S5EwI-00018f-LB for qemu-devel@nongnu.org; Wed, 07 Mar 2012 06:21:56 -0500 Received: from mail-ee0-f45.google.com ([74.125.83.45]:46224) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S5EwI-00018V-CM for qemu-devel@nongnu.org; Wed, 07 Mar 2012 06:21:50 -0500 Received: by eeit10 with SMTP id t10so2594753eei.4 for ; Wed, 07 Mar 2012 03:21:48 -0800 (PST) Sender: Paolo Bonzini Message-ID: <4F5744C9.8010308@redhat.com> Date: Wed, 07 Mar 2012 12:21:45 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <20120210143639.GA17883@gmail.com> <4F54E620.8060400@tuxadero.com> <4F54ED84.7030601@tuxadero.com> <4F573AFE.40204@tuxadero.com> In-Reply-To: <4F573AFE.40204@tuxadero.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] virtio-blk performance regression and qemu-kvm List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Martin Mailand Cc: Stefan Hajnoczi , reeted@shiftmail.org, qemu-devel@nongnu.org, kvm@vger.kernel.org Il 07/03/2012 11:39, Martin Mailand ha scritto: > The host disk can at max. 13K iops, in qemu I get at max 6,5K iops, > that's around about 50% overhead. All the test were with 4k reads, so I > think we are mostly latency bound. For latency tests, running without ioeventfd could give slightly better results (-global virtio-blk-pci.ioeventfd=off). Paolo