From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43625) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WV5S5-000850-3e for qemu-devel@nongnu.org; Tue, 01 Apr 2014 16:38:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WV5Rw-0002ku-1a for qemu-devel@nongnu.org; Tue, 01 Apr 2014 16:38:33 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:39502 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WV5Rv-0002kj-OA for qemu-devel@nongnu.org; Tue, 01 Apr 2014 16:38:23 -0400 Message-ID: <533B23B1.1040903@kamp.de> Date: Tue, 01 Apr 2014 22:38:09 +0200 From: Peter Lieven MIME-Version: 1.0 References: <1396017982-7390-1-git-send-email-pl@kamp.de> <53359B12.3030008@redhat.com> In-Reply-To: <53359B12.3030008@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCHv2] block: optimize zero writes with bdrv_write_zeroes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, armbru@redhat.com, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com Am 28.03.2014 16:53, schrieb Eric Blake: > On 03/28/2014 08:46 AM, Peter Lieven wrote: >> this patch tries to optimize zero write requests >> by automatically using bdrv_write_zeroes if it is >> supported by the format. >> >> This significantly speeds up file system initialization and >> should speed zero write test used to test backend storage >> performance. >> >> block.c | 39 ++++++++++++++++++++++++++++++++++++++- >> include/block/block_int.h | 12 ++++++++++++ >> include/qemu-common.h | 1 + >> qemu-options.hx | 6 ++++++ >> util/iov.c | 21 +++++++++++++++++++++ >> 5 files changed, 78 insertions(+), 1 deletion(-) >> > Is there any QMP query- command that can expose the current setting of > this value? Is this something worth making changeable during runtime? > Is it something that can be requested per-disk at hotplug time? currently there is no qmp query command I would add it to "query-block" if noone has objections. I don't think that its needed to change this at runtime. Setting it at hotplug time is, of course, reasonable. I will look at this and send a respin. Thanks for the suggestions, Peter