Re: [Qemu-devel] [PATCH v3 0/4] Fix -icount with iothread

[Edgar E. Iglesias]

On Tue, Apr 12, 2011 at 03:26:39PM +0200, Paolo Bonzini wrote:
> On 04/12/2011 11:26 AM, Jan Kiszka wrote:
> > On 2011-04-12 10:44, Paolo Bonzini wrote:
> >> This series finally fixes -icount with iothread and avoids deadlocks
> >> due to the vm_clock not making progress when the VM is stopped.
> >> The crux of the fix is in patch 1, while patch 2 implements the
> >> "clock warping" that fixes deadlocks in v2.  Clock warping uses
> >> the nanosecond resolution rt_clock timers introduced by my previous
> >> series.
> >>
> >> With this in place, patch 3 can revert the previous attempt(s).
> >> Finally, patch 4 makes the icount code clearer by finishing the
> >> bugfix/reorganization of qemu_next_deadline vs. qemu_next_alarm_deadline.
> >>
> >> v1->v2:
> >>          reordered patches, renamed qemu_next_deadline
> >>
> >> v2->v3:
> >>          introduced warp timer
> >>
> >> Paolo Bonzini (4):
> >>    really fix -icount in the iothread case
> >>    enable vm_clock to "warp" in the iothread+icount case
> >>    Revert wrong fixes for -icount in the iothread case
> >>    qemu_next_deadline should not consider host-time timers
> >>
> >>   cpus.c        |   13 ++++-
> >>   qemu-common.h |    1 +
> >>   qemu-timer.c  |  145 
> >> ++++++++++++++++++++++++++++++++++++++++++---------------
> >>   qemu-timer.h  |    3 +-
> >>   4 files changed, 121 insertions(+), 41 deletions(-)
> >>
> >
> > On first glance, I've spotted a view coding style issues. Try checkpatch
> > (maybe excluding patch 3).
> 
> Will repost, testing is welcome in the meanwhile!

The logic of the patches looks good to me, but it would be nice if you
could add a comment in the code regarding why we do the "warping". I think
parts of it could be based from the commit message.

I also tested the code and it works beautifully for my testcases!
iothread & icount ran faster than icount without iothread.

Thanks alot, cheers