Re: [Qemu-devel] [RFC PATCH v7 12/21] replay: recording and replaying clock ticks

[Pavel Dovgaluk]

> From: Paolo Bonzini [mailto:address@hidden
> On 19/01/2015 14:01, Pavel Dovgaluk wrote:
> > > It would be easier if you pointed me to actual code in the series.  But
> > > this doesn't seem impossible to fix by atomically writing the 'E' and
> > > 'A' in the same critical section.
> >
> > Because 'A' is written only inside some of the replay_run_event callbacks.
> > It depends on type of the event and it's processing function inside the 
> > QEMU core.
> > There could be no 'A' at all.
> 
> Why can't that code write the 'E' as well?

Because such callbacks do not know that they are called from record/replay 
event.
They may be called from record/replay code and from other parts of QEMU.
And they may write save something low-level like timer request.

Pavel Dovgalyuk