From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37650) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YzN9e-00006M-0K for qemu-devel@nongnu.org; Mon, 01 Jun 2015 06:41:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YzN9d-0002Mo-3e for qemu-devel@nongnu.org; Mon, 01 Jun 2015 06:41:13 -0400 Message-ID: <556C36BC.1000409@redhat.com> Date: Mon, 01 Jun 2015 12:41:00 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1430746944-27347-1-git-send-email-den@openvz.org> <20150511150817.GK16270@stefanha-thinkpad.redhat.com> <5550D3B5.2050703@openvz.org> <5550DD2D.8000407@odin.com> <20150512100155.GB11497@stefanha-thinkpad.redhat.com> <5551D39E.1020902@odin.com> <5551DA21.7020105@redhat.com> <20150513154342.GB24352@stefanha-thinkpad.redhat.com> <55538001.90207@odin.com> <5568974C.6080502@redhat.com> <877frn90pz.fsf@openvz.org> In-Reply-To: <877frn90pz.fsf@openvz.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v5 0/2] block: enforce minimal 4096 alignment in qemu_blockalign List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Dmitry Monakhov , "Denis V. Lunev" , Stefan Hajnoczi Cc: Dmitry Monakhov , Stefan Hajnoczi , qemu-block@nongnu.org, qemu-devel@nongnu.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 01/06/2015 12:34, Dmitry Monakhov wrote: > Yes. Improvement is not huge, but it can be detected for old qemu=20 > unpatched kernel: 728 MiB/sec =B1 20Mb patched kernel : 748 MiB/sec > =B1 10Mb Ok, so about 3-4%. What does the blktrace look like with a patched kernel, and what is the performance with old QEMU? Paolo > IMHO patch is not sufficient. We have to correct bio construction > inside direct-io code. I'll be back with the patch.