From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1KyU8C-0004sl-Nj
	for qemu-devel@nongnu.org; Fri, 07 Nov 2008 11:24:20 -0500
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1KyU8B-0004s9-5E
	for qemu-devel@nongnu.org; Fri, 07 Nov 2008 11:24:20 -0500
Received: from [199.232.76.173] (port=51756 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1KyU8B-0004rn-0F
	for qemu-devel@nongnu.org; Fri, 07 Nov 2008 11:24:19 -0500
Received: from mail.codesourcery.com ([65.74.133.4]:41572)
	by monty-python.gnu.org with esmtps
	(TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60)
	(envelope-from <paul@codesourcery.com>) id 1KyU8A-00053E-L0
	for qemu-devel@nongnu.org; Fri, 07 Nov 2008 11:24:18 -0500
From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] [5636] Run timers from host alarm timer callback
Date: Fri, 7 Nov 2008 17:23:54 +0100
References: <E1KxpYJ-0001Cj-Mu@cvs.savannah.gnu.org>
	<3e1533500811070352x2c3430b9k1eab7af8795f163d@mail.gmail.com>
	<49144B66.8080601@codemonkey.ws>
In-Reply-To: <49144B66.8080601@codemonkey.ws>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200811071623.55383.paul@codesourcery.com>
Reply-To: qemu-devel@nongnu.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.gnu.org/pipermail/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: qemu-devel@nongnu.org

On Friday 07 November 2008, Anthony Liguori wrote:
> Luis Pureza wrote:
> > Hi,
> >
> > This commit caused a noticeable slowdown while using the instruction
> > counting mechanism. I'm testing with the sparc-test image and with
> > --icount auto.
>
> Yeah, I take it that all timers don't result in signals when using
> icount and that we rely on select() timeout instead.  Let me look a
> little more closely at the code and I'll come up with a fix.

In icount mode vm_clock timers don't use host timers at all.

Instead we calculate how long we want to wait before checking again (the 
EXCP_HALT code in vl.c:main_loop), and use that as the select timeout.

Paul