Am 07.06.2019 um 13:18 hat Vladimir Sementsov-Ogievskiy geschrieben:
> 07.06.2019 10:57, Kevin Wolf wrote:
> > Am 11.04.2019 um 19:27 hat Vladimir Sementsov-Ogievskiy geschrieben:
> >> Introduce a function to gracefully wake-up a coroutine, sleeping in
> >> qemu_co_sleep_ns() sleep.
> >>
> >> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
> >
> > You can simply reenter the coroutine while it has yielded in
> > qemu_co_sleep_ns(). This is supported.
>
> No it doesn't. qemu_aio_coroutine_enter checks for scheduled field,
> and aborts if it is set.
Ah, yes, it has been broken since commit
I actually tried to fix it once, but it turned out more complicated and
I think we found a different solution for the problem at hand:
Subject: [PATCH for-2.11 0/4] Fix qemu-iotests failures
Message-Id: <20171128154350.21504-1-kw...@redhat.com>
In this case, I guess your approach with a new function to interrupt
qemu_co_sleep_ns() is okay.
Do we need to timer_del() when taking the shortcut? We don't necessarily
reenter the coroutine immediately, but might only be scheduling it. In
this case, the timer could fire before qemu_co_sleep_ns() has run and
schedule the coroutine a second time (ignoring co->scheduled again -
maybe we should actually not do that in the timer callback path, but
instead let it run into the assertion because it would be a bug for the
timer callback to end up in this situation).
Kevin
