[Qemu-devel] Re: [PATCH v2 0/3] really fix -icount with iothread

[Edgar E. Iglesias]

On Thu, Mar 10, 2011 at 01:12:48PM +0100, Paolo Bonzini wrote:
> This is a "real" fix for -icount, real in the sense that it
> works in all cases including those that weren't fixed by my
> first attempt.
> 
> Patch 1 is the three-line fix.  With that in, patch 2 can revert
> the previous attempt(s).  Finally, patch 3 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


Hi Paulo,

I gave this patchset a run and it runs icount and iothread very
fast in all my testcases.

But, it suffers from the problem that commit
225d02cd1a34d5d87e8acefbf8e244a5d12f5f8c
tried to fix.

If the virtual CPU goes to sleep waiting for a future timer
interrupt to wake it up, qemu deadlocks.

The timer interrupt never comes because time is driven by
icount, but the vCPU doesn't run any insns.

Cheers