On Tue 19 Sep 2017 05:50:25 PM CEST, Stefan Hajnoczi wrote: > Clear tg->any_timer_armed[] when throttling timers are destroy during > AioContext attach/detach. Failure to do so causes throttling to hang > because we believe the timer is already scheduled! > > The following was broken at least since QEMU 2.10.0 with -drive > iops=100: > > $ dd if=/dev/zero of=/dev/vdb oflag=direct count=1000 > (qemu) stop > (qemu) cont > ...I/O is stuck... > > Reported-by: Yongxue Hong <yh...@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> > --- > block/throttle-groups.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/block/throttle-groups.c b/block/throttle-groups.c > index 6ba992c8d7..2bfd03faa0 100644 > --- a/block/throttle-groups.c > +++ b/block/throttle-groups.c > @@ -592,7 +592,20 @@ void > throttle_group_attach_aio_context(ThrottleGroupMember *tgm, > void throttle_group_detach_aio_context(ThrottleGroupMember *tgm) > { > ThrottleTimers *tt = &tgm->throttle_timers; > + ThrottleGroup *tg = container_of(tgm->throttle_state, ThrottleGroup, ts); > + > throttle_timers_detach_aio_context(tt); > + > + /* Forget about these timers, they have been destroyed */ > + qemu_mutex_lock(&tg->lock); > + if (tg->tokens[0] == tgm) { > + tg->any_timer_armed[0] = false; > + } > + if (tg->tokens[1] == tgm) { > + tg->any_timer_armed[1] = false; > + } > + qemu_mutex_unlock(&tg->lock);
I think I'd rather check the timers directly using timer_pending(). See https://github.com/qemu/qemu/blob/dbe824cc5/block/throttle-groups.c#L426 Berto