Re: [PATCH 09/11] iotests/264: add mirror-cancel test-case

[Vladimir Sementsov-Ogievskiy]

21.01.2021 04:26, Eric Blake wrote:
> On 11/18/20 12:04 PM, Vladimir Sementsov-Ogievskiy wrote:
> > Check that cancel doesn't wait for 10s of nbd reconnect timeout.
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> > ---
> >   tests/qemu-iotests/264     | 38 ++++++++++++++++++++++++++++++--------
> >   tests/qemu-iotests/264.out |  4 ++--
> >   2 files changed, 32 insertions(+), 10 deletions(-)
>
> >   
> > +    def test_mirror_cancel(self):
> > +        # Mirror speed limit doesn't work well enough, it seems that mirror
> > +        # will run many parallel requests anyway. MAX_IN_FLIGHT is 16 and
> > +        # MAX_IO_BYTES is 1M in mirror.c, so let's use 20M disk.
> > +        self.init_vm(20 * 1024 * 1024)
> > +        self.start_job('blockdev-mirror')
>
> Is this comment still accurate given recent work on the mirror filter?

Hmm, what do you mean? I missed it..

> I'm fine taking the patch as-is and tweaking it with followups, though,
> in order to make progress.

Good for me, of course

> > +
> > +        result = self.vm.qmp('block-job-cancel', device='drive0')
> > +        self.assert_qmp(result, 'return', {})
> > +
> > +        start_t = time.time()
> > +        self.vm.event_wait('BLOCK_JOB_CANCELLED')
> > +        delta_t = time.time() - start_t
> > +        self.assertTrue(delta_t < 2.0)
>
> I hope this doesn't fail on CI platforms under heavy load.  It didn't
> fail for me locally, but I hope we don't have to revisit it.  Is there
> any way we can test this in a manner that is not as fragile?

Hmm, I don't know. We want to check that cancel is not as long as reconnect 
timeout.. If it fails, we'll adjust the constants :) And we have no limit in 
it, we can use 1hour for reconnect-timeout and 10min for mirror to cancel for 
example (but probably something other may fail with such big timeouts)

> Reviewed-by: Eric Blake <eblake@redhat.com>


--
Best regards,
Vladimir