From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34446) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V2Km1-0004iq-1t for qemu-devel@nongnu.org; Thu, 25 Jul 2013 08:36:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V2Klz-0002lO-Ox for qemu-devel@nongnu.org; Thu, 25 Jul 2013 08:36:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:24843) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V2Klz-0002ku-Df for qemu-devel@nongnu.org; Thu, 25 Jul 2013 08:35:59 -0400 Message-ID: <51F11B94.8090400@redhat.com> Date: Thu, 25 Jul 2013 14:35:32 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1374396185-10870-1-git-send-email-pingfank@linux.vnet.ibm.com> <20130725120530.GJ21033@stefanha-thinkpad.redhat.com> <51F11AFB.9040008@siemens.com> In-Reply-To: <51F11AFB.9040008@siemens.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC 0/8] arm AioContext with its own timer stuff List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Kevin Wolf , Alex Bligh , Stefan Hajnoczi , Liu Ping Fan , qemu-devel@nongnu.org, Stefan Hajnoczi , Anthony Liguori Il 25/07/2013 14:32, Jan Kiszka ha scritto: > On 2013-07-25 14:21, Alex Bligh wrote: >> >> >> --On 25 July 2013 14:05:30 +0200 Stefan Hajnoczi >> wrote: >> >>> Alex Bligh's series gives each AioContext its own rt_clock. This avoids >>> the need for synchronization in the simple case. If we require timer >>> access between threads then we really need to synchronize. >>> >>> You pointed out in another email that vm_clock stops when the guest is >>> paused. I think we can find a solution for I/O throttling and QED, >>> which use vm_clock in the block layer. Note that block jobs already use >>> rt_clock. >> >> I would happily at a QEMUClock of each type to AioContext. They are after >> all pretty lightweight. > > What's the point of adding tones of QEMUClock instances? Considering > proper abstraction, how are they different for each AioContext? Will > they run against different clock sources, start/stop at different times? > If the answer is "they have different timer list", then fix this > incorrect abstraction. s/QEMUClock/QEMUTimerList/ ? :) Paolo