From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Wolf Subject: Re: [Qemu-devel] [PATCH 0/2] improve qemu-img conversion performance Date: Mon, 12 Sep 2011 10:05:05 +0200 Message-ID: <4E6DBD31.5050702@redhat.com> References: <4E68CD7E.2050704@redhat.com> <4E69CBDB.1000401@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:13423 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752874Ab1ILICJ (ORCPT ); Mon, 12 Sep 2011 04:02:09 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Yehuda Sadeh Weinraub Cc: Sage Weil , qemu-devel@nongnu.org, ceph-devel@vger.kernel.org Am 12.09.2011 05:17, schrieb Yehuda Sadeh Weinraub: > On Sun, Sep 11, 2011 at 8:14 PM, Sage Weil wrote: >> On Fri, 9 Sep 2011, Kevin Wolf wrote: >>> Am 08.09.2011 18:36, schrieb Sage Weil: >>>> On Thu, 8 Sep 2011, Kevin Wolf wrote: >>>>> Am 08.09.2011 01:06, schrieb Yehuda Sadeh: >>>>>> The following set of patches improve the qemu-img conversion process >>>>>> performance. When using a higher latency backend, small writes have a >>>>>> severe impact on the time it takes to do image conversion. >>>>>> We switch to using async writes, and we avoid splitting writes due to >>>>>> holes when the holes are small enough. >>>>>> >>>>>> Yehuda Sadeh (2): >>>>>> qemu-img: async write to block device when converting image >>>>>> qemu-img: don't skip writing small holes >>>>>> >>>>>> qemu-img.c | 34 +++++++++++++++++++++++++++------- >>>>>> 1 files changed, 27 insertions(+), 7 deletions(-) >>>>>> >>>>> >>>>> This doesn't seem to be against git master or the block tree. Please rebase. >>>>> >>>>> I think that commit a22f123c may obsolete your patch 2/2. >>>> >>>> With git.kernel.org down, where should I be looking for the latest >>>> upstream? >>> >>> qemu has never been on kernel.org. The interesting repositories for you are: >>> >>> * Upstream: git://git.qemu.org/qemu.git master >>> * Block development branch: git://repo.or.cz/qemu/kevin.git block >> >> Oh right. I've been working from qemu-kvm.git. >> >> I've done some (still minimal) testing, and it looks like the combination >> of a22f123c and the new writeback/flush stuff in librbd gets the same >> result as doing async io explicitly from qemu-img.c. Want to take a look, >> Yehuda? It still defaults to off, so you'll need to add >> rbd_writeback_window=8000000 or similar to the rbd device string. >> > > I'll take a look. I do have a rebased version for the qemu-img async > patch, and I think qemu can benefit from that anyway. Yes, I agree that the change makes sense anyway. Kevin From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:54541) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R31T3-0002Fd-S4 for qemu-devel@nongnu.org; Mon, 12 Sep 2011 04:02:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R31Sz-0007r4-4v for qemu-devel@nongnu.org; Mon, 12 Sep 2011 04:02:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:26018) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R31Sy-0007qu-Qa for qemu-devel@nongnu.org; Mon, 12 Sep 2011 04:02:09 -0400 Message-ID: <4E6DBD31.5050702@redhat.com> Date: Mon, 12 Sep 2011 10:05:05 +0200 From: Kevin Wolf MIME-Version: 1.0 References: <4E68CD7E.2050704@redhat.com> <4E69CBDB.1000401@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/2] improve qemu-img conversion performance List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yehuda Sadeh Weinraub Cc: Sage Weil , ceph-devel@vger.kernel.org, qemu-devel@nongnu.org Am 12.09.2011 05:17, schrieb Yehuda Sadeh Weinraub: > On Sun, Sep 11, 2011 at 8:14 PM, Sage Weil wrote: >> On Fri, 9 Sep 2011, Kevin Wolf wrote: >>> Am 08.09.2011 18:36, schrieb Sage Weil: >>>> On Thu, 8 Sep 2011, Kevin Wolf wrote: >>>>> Am 08.09.2011 01:06, schrieb Yehuda Sadeh: >>>>>> The following set of patches improve the qemu-img conversion process >>>>>> performance. When using a higher latency backend, small writes have a >>>>>> severe impact on the time it takes to do image conversion. >>>>>> We switch to using async writes, and we avoid splitting writes due to >>>>>> holes when the holes are small enough. >>>>>> >>>>>> Yehuda Sadeh (2): >>>>>> qemu-img: async write to block device when converting image >>>>>> qemu-img: don't skip writing small holes >>>>>> >>>>>> qemu-img.c | 34 +++++++++++++++++++++++++++------- >>>>>> 1 files changed, 27 insertions(+), 7 deletions(-) >>>>>> >>>>> >>>>> This doesn't seem to be against git master or the block tree. Please rebase. >>>>> >>>>> I think that commit a22f123c may obsolete your patch 2/2. >>>> >>>> With git.kernel.org down, where should I be looking for the latest >>>> upstream? >>> >>> qemu has never been on kernel.org. The interesting repositories for you are: >>> >>> * Upstream: git://git.qemu.org/qemu.git master >>> * Block development branch: git://repo.or.cz/qemu/kevin.git block >> >> Oh right. I've been working from qemu-kvm.git. >> >> I've done some (still minimal) testing, and it looks like the combination >> of a22f123c and the new writeback/flush stuff in librbd gets the same >> result as doing async io explicitly from qemu-img.c. Want to take a look, >> Yehuda? It still defaults to off, so you'll need to add >> rbd_writeback_window=8000000 or similar to the rbd device string. >> > > I'll take a look. I do have a rebased version for the qemu-img async > patch, and I think qemu can benefit from that anyway. Yes, I agree that the change makes sense anyway. Kevin