From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:48494)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1VTaai-0003v4-3p
	for qemu-devel@nongnu.org; Tue, 08 Oct 2013 12:57:06 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1VTaac-0006tw-5F
	for qemu-devel@nongnu.org; Tue, 08 Oct 2013 12:57:00 -0400
Received: from mx1.redhat.com ([209.132.183.28]:6517)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1VTaab-0006tb-Tg
	for qemu-devel@nongnu.org; Tue, 08 Oct 2013 12:56:54 -0400
Message-ID: <5254394B.506@redhat.com>
Date: Tue, 08 Oct 2013 18:56:43 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
MIME-Version: 1.0
References: <1381222058-16701-1-git-send-email-pbonzini@redhat.com>
	<1381222058-16701-6-git-send-email-pbonzini@redhat.com>
	<703C02BF-B3A3-493A-8713-7979746C6811@alex.org.uk>
In-Reply-To: <703C02BF-B3A3-493A-8713-7979746C6811@alex.org.uk>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH 5/8] timers: prepare the code for future
 races in calling qemu_clock_warp
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/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: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Alex Bligh <alex@alex.org.uk>
Cc: qemu-devel@nongnu.org

Il 08/10/2013 18:54, Alex Bligh ha scritto:
>> > -
>> > -    /* Maintain prior (possibly buggy) behaviour where if no deadline
>> > -     * was set (as there is no QEMU_CLOCK_VIRTUAL timer) or it is more than
>> > -     * INT32_MAX nanoseconds ahead, we still use INT32_MAX
>> > -     * nanoseconds.
>> > -     */
>> > -    if ((deadline < 0) || (deadline > INT32_MAX)) {
>> > -        deadline = INT32_MAX;
>> > +    if (deadline < 0) {
>> > +        return;
>> >     }
> 
> Arguably the patch could document why removing the check for deadline > INT32_MAX
> (the bug for bug compatibility) is safe, as I couldn't entirely convince myself it
> was, mostly because I couldn't see why it was doing it in the first place.

I couldn't convince myself that it is _not_ safe :) and it made the code
more complicated.  As soon as a deadline appears, qemu_clock_warp() will
be called again and update the icount_warp_timer.

Ok to move that to a separate patch?

Paolo