From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57357) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ve2Uv-0003is-5F for qemu-devel@nongnu.org; Wed, 06 Nov 2013 07:46:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ve2Um-00069v-MI for qemu-devel@nongnu.org; Wed, 06 Nov 2013 07:46:13 -0500 Received: from mail-qe0-x22e.google.com ([2607:f8b0:400d:c02::22e]:57535) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ve2Um-00069r-Ix for qemu-devel@nongnu.org; Wed, 06 Nov 2013 07:46:04 -0500 Received: by mail-qe0-f46.google.com with SMTP id s14so6005524qeb.5 for ; Wed, 06 Nov 2013 04:46:04 -0800 (PST) Sender: Paolo Bonzini Message-ID: <527A3A07.2090207@redhat.com> Date: Wed, 06 Nov 2013 13:45:59 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1383740591-27739-1-git-send-email-charlie@ctshepherd.com> In-Reply-To: <1383740591-27739-1-git-send-email-charlie@ctshepherd.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/3] COW: Speed up writes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Charlie Shepherd Cc: kwolf@redhat.com, stefanha@gmail.com, gabriel@kerneis.info, qemu-devel@nongnu.org Il 06/11/2013 13:23, Charlie Shepherd ha scritto: > Patch 2 was written initially I was intending to use cow_co_is_allocated in > Patch 3 and needed it to consider all sectors but in the end cow_find_streak > was sufficient, so it may not strictly be necessary. Patch 2 can still speed up reads that cross a sector boundary from 4 I/O operations (2 for the bitmap, 2 for the data) to 3 (only 1 for the data). Paolo