Re: [PATCH 4/7] iotests/129: Use throttle node

[Max Reitz <mreitz@redhat.com>]

On 13.01.21 17:46, Vladimir Sementsov-Ogievskiy wrote:
> 13.01.2021 17:06, Max Reitz wrote:
>> Throttling on the BB has not affected block jobs in a while, so it is
>> possible that one of the jobs in 129 finishes before the VM is stopped.
>> We can fix that by running the job from a throttle node.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>   tests/qemu-iotests/129 | 39 +++++++++++++++------------------------
>>   1 file changed, 15 insertions(+), 24 deletions(-)
>>
>> diff --git a/tests/qemu-iotests/129 b/tests/qemu-iotests/129
>> index dd23bb2e5a..febc806398 100755
>> --- a/tests/qemu-iotests/129
>> +++ b/tests/qemu-iotests/129
>> @@ -32,20 +32,18 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
>>           iotests.qemu_img('create', '-f', iotests.imgfmt, self.test_img,
>>                            "-b", self.base_img, '-F', iotests.imgfmt)
>>           iotests.qemu_io('-f', iotests.imgfmt, '-c', 'write -P0x5d 1M 
>> 128M', self.test_img)
>> -        self.vm = iotests.VM().add_drive(self.test_img)
>> +        self.vm = iotests.VM()
>> +        self.vm.add_object('throttle-group,id=tg0,x-bps-total=1024')
>> +
>> +        source_drive = 'driver=throttle,' + \
>> +                       'throttle-group=tg0,' + \
>> +                      f'file.driver={iotests.imgfmt},' + \
>> +                      f'file.file.filename={self.test_img}'
> 
> python has a "c-like" string "concatenation", i.e., you may omit "+" 
> operators (I don't know is it a good practice, but I do so:)

OK, why not.

>> +
>> +        self.vm.add_drive(None, source_drive)
>>           self.vm.launch()
>>       def tearDown(self):
>> -        params = {"device": "drive0",
>> -                  "bps": 0,
>> -                  "bps_rd": 0,
>> -                  "bps_wr": 0,
>> -                  "iops": 0,
>> -                  "iops_rd": 0,
>> -                  "iops_wr": 0,
>> -                 }
>> -        result = self.vm.qmp("block_set_io_throttle", conv_keys=False,
>> -                             **params)
>>           self.vm.shutdown()
>>           for img in (self.test_img, self.target_img, self.base_img):
>>               iotests.try_remove(img)
>> @@ -53,33 +51,26 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
>>       def do_test_stop(self, cmd, **args):
>>           """Test 'stop' while block job is running on a throttled drive.
>>           The 'stop' command shouldn't drain the job"""
>> -        params = {"device": "drive0",
>> -                  "bps": 1024,
>> -                  "bps_rd": 0,
>> -                  "bps_wr": 0,
>> -                  "iops": 0,
>> -                  "iops_rd": 0,
>> -                  "iops_wr": 0,
>> -                 }
>> -        result = self.vm.qmp("block_set_io_throttle", conv_keys=False,
>> -                             **params)
>> -        self.assert_qmp(result, 'return', {})
>>           result = self.vm.qmp(cmd, **args)
>>           self.assert_qmp(result, 'return', {})
>> +
>>           result = self.vm.qmp("stop")
>>           self.assert_qmp(result, 'return', {})
>>           result = self.vm.qmp("query-block-jobs")
>> +
>>           self.assert_qmp(result, 'return[0]/status', 'running')
>>           self.assert_qmp(result, 'return[0]/ready', False)
>> +        self.vm.qmp("block-job-cancel", device="drive0", force=True)
> 
> won't hurt, but I'd drop it as unrelated to commit
> 
>> +
>>       def test_drive_mirror(self):
>>           self.do_test_stop("drive-mirror", device="drive0",
>> -                          target=self.target_img,
>> +                          target=self.target_img, format=iotests.imgfmt,
>>                             sync="full")
> 
> this doesn't seem need/related too..

It is, because without a @format parameter, the job uses the driver of 
@device as the output format.  That driver is now 'throttle', which 
doesn’t work as a format.

Max