From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=44637 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1Oaq9A-0002ZK-4l
	for qemu-devel@nongnu.org; Mon, 19 Jul 2010 09:12:44 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69)
	(envelope-from <gleb@redhat.com>) id 1Oaq97-0001Kx-NC
	for qemu-devel@nongnu.org; Mon, 19 Jul 2010 09:12:40 -0400
Received: from mx1.redhat.com ([209.132.183.28]:7678)
	by eggs.gnu.org with esmtp (Exim 4.69)
	(envelope-from <gleb@redhat.com>) id 1Oaq97-0001Kp-GI
	for qemu-devel@nongnu.org; Mon, 19 Jul 2010 09:12:37 -0400
Date: Mon, 19 Jul 2010 16:12:34 +0300
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [Qemu-devel] Question about qemu firmware configuration
	(fw_cfg) device
Message-ID: <20100719131234.GU4689@redhat.com>
References: <20100719073312.GY4689@redhat.com>
	<20100719074416.GP13194@amd.home.annexia.org>
	<20100719075533.GC4689@redhat.com>
	<20100719083411.GR13194@amd.home.annexia.org>
	<20100719084041.GH4689@redhat.com>
	<20100719090004.GS13194@amd.home.annexia.org>
	<20100719090654.GK4689@redhat.com>
	<9C4457B3-884D-482D-9BD0-C49AA20FB3CF@suse.de>
	<20100719091543.GM4689@redhat.com>
	<20100719130627.GA3326@amd.home.annexia.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20100719130627.GA3326@amd.home.annexia.org>
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: "Richard W.M. Jones" <rjones@redhat.com>
Cc: Alexander Graf <agraf@suse.de>, qemu-devel@nongnu.org

On Mon, Jul 19, 2010 at 02:06:27PM +0100, Richard W.M. Jones wrote:
> On Mon, Jul 19, 2010 at 12:15:43PM +0300, Gleb Natapov wrote:
> > That what we are talking about, no? We are trying to find faster way to
> > load kernel/initrd and stay architectural. Honestly I would expect much
> > greater speedup from Richard's approach like 2 seconds vs 8 seconds. It
> > is hard to justify code complication just for 1 second speedup.
> 
> I've no idea where this "8 seconds" comes from.  Total boot time
That was number generated by may random number generator. I was just
trying to say that I would have expected much more gain from copying
kernel/initrd directly into the memory considering how much is going
on during pio string emulation.

> currently is < 8 seconds even without my patch.  My patch takes it
> from 7.5 seconds to 6.5 seconds.
> 
It shows that we are not so bad at emulating pio string operations.

--
			Gleb.