From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:41317)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1V2I0l-0000nv-Ui
	for qemu-devel@nongnu.org; Thu, 25 Jul 2013 05:39:05 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1V2I0k-0005aN-Oj
	for qemu-devel@nongnu.org; Thu, 25 Jul 2013 05:39:03 -0400
Received: from mx1.redhat.com ([209.132.183.28]:31540)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1V2I0j-0005aD-I8
	for qemu-devel@nongnu.org; Thu, 25 Jul 2013 05:39:02 -0400
Message-ID: <51F0F21B.7090409@redhat.com>
Date: Thu, 25 Jul 2013 11:38:35 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
MIME-Version: 1.0
References: <1E8E204.8000201@redhat.com>
	<1374343603-29183-1-git-send-email-alex@alex.org.uk>
	<1374343603-29183-2-git-send-email-alex@alex.org.uk>
	<20130725091015.GC21033@stefanha-thinkpad.redhat.com>
	<F5466B4B7A40B45894477D5E@nimrod.local>
In-Reply-To: <F5466B4B7A40B45894477D5E@nimrod.local>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCHv2] [RFC 1/7] aio / timers: Remove alarm
	timers
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: Kevin Wolf <kwolf@redhat.com>, Anthony Liguori <aliguori@us.ibm.com>, Stefan Hajnoczi <stefanha@gmail.com>, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>, rth@twiddle.net

Il 25/07/2013 11:37, Alex Bligh ha scritto:
> Stefan,
> 
>> This should be one of the last patches so qemu.git remains bisectable.
>> Only remove the alarm timer once the event loops are already using the
>> timeout argument.
> 
> OK
> 
>>> @@ -245,11 +82,7 @@ static QEMUClock *qemu_new_clock(int type)
>>>
>>>  void qemu_clock_enable(QEMUClock *clock, bool enabled)
>>>  {
>>> -    bool old = clock->enabled;
>>>      clock->enabled = enabled;
>>> -    if (enabled && !old) {
>>> -        qemu_rearm_alarm_timer(alarm_timer);
>>> -    }
>>
>> If this function is supposed to work when called from another thread
>> (e.g. vcpu thread), then you need to call qemu_notify_event().  For
>> AioContext clocks that should be aio_notify() with the relevant
>> AioContext, but we don't need that yet.
> 
> Each AioContext knows which clock it has but each clock doesn't know if
> it's part of an AioContext. I suggest this is infrequent enough that always
> using qemu_notify_event() would be OK. That should interrupt any poll.

No, qemu_notify_event() only interrupts the main clock's poll.

Paolo