Re: [PATCH v2] iotests.py: Let wait_migration wait even more

[Max Reitz <mreitz@redhat.com>]

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On 20.12.19 10:32, Kevin Wolf wrote:
> Am 19.12.2019 um 19:36 hat Max Reitz geschrieben:
>> The "migration completed" event may be sent (on the source, to be
>> specific) before the migration is actually completed, so the VM runstate
>> will still be "finish-migrate" instead of "postmigrate".  So ask the
>> users of VM.wait_migration() to specify the final runstate they desire
>> and then poll the VM until it has reached that state.  (This should be
>> over very quickly, so busy polling is fine.)
>>
>> Without this patch, I see intermittent failures in the new iotest 280
>> under high system load.  I have not yet seen such failures with other
>> iotests that use VM.wait_migration() and query-status afterwards, but
>> maybe they just occur even more rarely, or it is because they also wait
>> on the destination VM to be running.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
> 
>> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
>> index 13fd8b5cd2..0b62c42851 100644
>> --- a/tests/qemu-iotests/iotests.py
>> +++ b/tests/qemu-iotests/iotests.py
>> @@ -668,12 +668,16 @@ class VM(qtest.QEMUQtestMachine):
>>              }
>>          ]))
>>  
>> -    def wait_migration(self):
>> +    def wait_migration(self, expect_runstate):
>>          while True:
>>              event = self.event_wait('MIGRATION')
>>              log(event, filters=[filter_qmp_event])
>>              if event['data']['status'] == 'completed':
>>                  break
>> +        # The event may occur in finish-migrate, so wait for the expected
>> +        # post-migration runstate
> 
> That's a bit too specific now that you have expect_runstate.

Can you be more specific? :-)

If you mean the fact of mentioning “post-migration runstate”, I simply
meant that as “the runstate after the migration”.  The specific runstate
on the source VM is called “postmigrate”.

I wouldn’t mind changing it to “after-migration runstate” or something
similar, if that’s what you mean.

Max

>> +        while self.qmp('query-status')['return']['status'] != expect_runstate:
>> +            pass
>>  
>>      def node_info(self, node_name):
>>          nodes = self.qmp('query-named-block-nodes')
> 
> Tested-by: Kevin Wolf <kwolf@redhat.com>
> 



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