From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1NeqvL-0005q9-D3
	for qemu-devel@nongnu.org; Tue, 09 Feb 2010 09:18:43 -0500
Received: from [199.232.76.173] (port=40217 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1NeqvK-0005pk-VC
	for qemu-devel@nongnu.org; Tue, 09 Feb 2010 09:18:43 -0500
Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim
	4.60) (envelope-from <avi@redhat.com>) id 1NeqvJ-0006gC-US
	for qemu-devel@nongnu.org; Tue, 09 Feb 2010 09:18:42 -0500
Received: from mx1.redhat.com ([209.132.183.28]:34080)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <avi@redhat.com>) id 1NeqvJ-0006fE-Is
	for qemu-devel@nongnu.org; Tue, 09 Feb 2010 09:18:41 -0500
Message-ID: <4B716EB9.2060006@redhat.com>
Date: Tue, 09 Feb 2010 16:18:33 +0200
From: Avi Kivity <avi@redhat.com>
MIME-Version: 1.0
References: <20100209012851.GJ25751@x200.localdomain>
	<4B710714.1020109@redhat.com>
In-Reply-To: <4B710714.1020109@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: [Qemu-devel] Re: KVM call agenda for Feb 9
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: Chris Wright <chrisw@redhat.com>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org

On 02/09/2010 08:56 AM, Avi Kivity wrote:
> On 02/09/2010 03:28 AM, Chris Wright wrote:
>> Please send in any agenda items you are interested in covering.
>
> hpet overhead on large smp guests
>
> I measured hpet consuming about a half a core's worth of cpu on an 
> idle Windows 2008 R2 64-way guest.  This is mostly due to futex 
> contention, likely from the qemu mutex.
>
> Options:
> - ignore, this is about 1% of the entire system (but overhead might 
> increase greatly if a workload triggers more hpet accesses)
> - push hpet into kernel, with virtio-net, virtio-blk, and kernel-hpet, 
> there's little reason to exit into qemu
> - rcuify/fine-grain qemu locks
>
- implement hyper-v timers


-- 
error compiling committee.c: too many arguments to function