From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1KPKn0-00077g-JI
	for qemu-devel@nongnu.org; Sat, 02 Aug 2008 13:21:10 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1KPKmy-00073J-Hi
	for qemu-devel@nongnu.org; Sat, 02 Aug 2008 13:21:10 -0400
Received: from [199.232.76.173] (port=45398 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1KPKmy-00072z-Cg
	for qemu-devel@nongnu.org; Sat, 02 Aug 2008 13:21:08 -0400
Received: from mtaout01-winn.ispmail.ntl.com ([81.103.221.47]:14055)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <samuel.thibault@labri.fr>) id 1KPKmx-0000me-Th
	for qemu-devel@nongnu.org; Sat, 02 Aug 2008 13:21:08 -0400
Date: Sat, 2 Aug 2008 18:21:03 +0100
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Subject: Re: [Qemu-devel] [RFC][PATCH] Add HPET emulation to qemu (v2)
Message-ID: <20080802172103.GH4535@implementation>
References: <1217675114-17670-1-git-send-email-eak@us.ibm.com>
	<20080802113812.GD4535@implementation>
	<48947346.5080605@codemonkey.ws>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <48947346.5080605@codemonkey.ws>
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: Anthony Liguori <anthony@codemonkey.ws>
Cc: Beth Kon <eak@us.ibm.com>, qemu-devel@nongnu.org, kvm@vger.kernel.org, Alexander Graf <agraf@suse.de>

Anthony Liguori, le Sat 02 Aug 2008 09:46:30 -0500, a écrit :
> Samuel Thibault wrote:
> >Beth Kon, le Sat 02 Aug 2008 06:05:14 -0500, a écrit :
> >  
> >>I was trying to reproduce the wakeup every 10ms that 
> >>Samuel Thibault mentioned, thinking the HPET would improve it. 
> >>But for an idle guest in both cases (with and without HPET), the 
> >>number of wakeups per second was relatively low (28).
> >>    
> >
> >I was referring to vl.c's timeout = 10; which makes the select call
> >use a timeout of 10ms. That said, "/* If all cpus are halted then wait
> >until the next IRQ */", so maybe that's why you get slower wakeups per
> >second.  I'm still surprised because of the call to qemu_mod_timer in
> >pit_irq_timer_update which should setup at least a 100Hz timer with
> >linux guests (when they don't have HPET available).
> >  
> 
> The patch disables that when hpet is active.

That's why I would expect, indeed, but he is reporting that _without_
HPET he gets low wakeups per second already.

Samuel