Il 08/07/2014 21:07, Christian Borntraeger ha scritto:
On 08/07/14 19:08, Paolo Bonzini wrote:
Il 08/07/2014 17:59, Stefan Hajnoczi ha scritto:
I sent Christian an initial patch to fix this but now both threads are
stuck in rfifolock_lock() inside cond wait. That's very strange and
should never happen.
I had this patch pending for 2.2:
commit 6c81e31615c3cda5ea981a998ba8b1b8ed17de6f
Author: Paolo Bonzini <pbonz...@redhat.com>
Date: Mon Jul 7 10:39:49 2014 +0200
iothread: do not rely on aio_poll(ctx, true) result to end a loop
Currently, whenever aio_poll(ctx, true) has completed all pending
work it returns true *and* the next call to aio_poll(ctx, true)
will not block.
This invariant has its roots in qemu_aio_flush()'s implementation
as "while (qemu_aio_wait()) {}". However, qemu_aio_flush() does
not exist anymore and bdrv_drain_all() is implemented differently;
and this invariant is complicated to maintain and subtly different
from the return value of GMainLoop's g_main_context_iteration.
All calls to aio_poll(ctx, true) except one are guarded by a
while() loop checking for a request to be incomplete, or a
BlockDriverState to be idle. Modify that one exception in
iothread.c.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
The hangs are gone. Looks like 2.1 material now...
Acked-by: Christian Borntraeger <borntrae...@de.ibm.com>
Tested-by: Christian Borntraeger <borntrae...@de.ibm.com>
Great, I'll send it out tomorrow morning.
Paolo
