From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [PATCH v3 1/3] Introduce a workqueue to deliver PIT timer
 interrupts.
Date: Tue, 17 Apr 2012 13:31:06 +0300
Message-ID: <20120417103106.GG11918@redhat.com>
References: <1276722673-19011-1-git-send-email-clalance@redhat.com>
 <1276722673-19011-2-git-send-email-clalance@redhat.com>
 <4F8C49D6.9010603@siemens.com>
 <20120417093123.GB11918@redhat.com>
 <4F8D44B8.1000102@redhat.com>
 <20120417102601.GF11918@redhat.com>
 <4F8D45F0.4020908@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: Jan Kiszka <jan.kiszka@siemens.com>, kvm@vger.kernel.org,
	Marcelo Tosatti <mtosatti@redhat.com>
To: Avi Kivity <avi@redhat.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mx1.redhat.com ([209.132.183.28]:30501 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1750888Ab2DQKbJ (ORCPT <rfc822;kvm@vger.kernel.org>);
	Tue, 17 Apr 2012 06:31:09 -0400
Content-Disposition: inline
In-Reply-To: <4F8D45F0.4020908@redhat.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On Tue, Apr 17, 2012 at 01:29:04PM +0300, Avi Kivity wrote:
> On 04/17/2012 01:26 PM, Gleb Natapov wrote:
> > > It isn't, since you need to send an IPI.
> > > 
> > That is exactly what I forget whether you can send IPI from there :)
> > Anyway this is another reason.
> >
> 
> Actually I was wrong.  You can't smp_call_function_single() from irq
> context (deadlocks if two vcpus do that), but we send a reschedule
> interrupt.  So it should work.
> 
Ah, good point. So if we'll use irqsave versions of spinlocks we can
drop kthread?

--
			Gleb.