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Date: Mon, 5 Jul 2010 15:20:25 +0300
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: [Qemu-devel] Re: [Bug 599958] Re: Timedrift problems with
	Win7: hpet missing time drift fixups
Message-ID: <20100705122025.GQ4689@redhat.com>
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To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Blue Swirl <blauwirbel@gmail.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, Avi Kivity <avi@redhat.com>, Paul Brook <paul@codesourcery.com>

On Mon, Jul 05, 2010 at 02:16:56PM +0200, Jan Kiszka wrote:
> Avi Kivity wrote:
> > On 07/05/2010 02:13 PM, Jan Kiszka wrote:
> >> That decoupling between state change and acknowledgment worries me.
> >> Dispatching a source to multiple sinks or sharing a sink between
> >> multiple source is no longer cleanly manageable this way. Just look at
> >> the route of some ISA IRQ on x86: You may get an 'ack' from IOAPIC side
> >> and a 'masked' from the ISA side (or vice versa). And the 'masked' will
> >> arrive earlier.
> > 
> > I think it is sufficient to only note masks and take action on acks.
> 
> We would increment our backlog on injection, decrement it on mask
> notification - and decrement it again on ack.
> 
On mask notification backlog is zeroed and not incremented until unmask
notification.

--
			Gleb.