Re: [Qemu-block] [PATCH v5 6/6] iotests: extend sleeping time under Valgrind

[John Snow]

On 8/28/19 11:24 AM, Andrey Shinkevich wrote:
> 
> 
> On 27/08/2019 22:42, John Snow wrote:
>>
>>
>> On 8/23/19 11:27 AM, Vladimir Sementsov-Ogievskiy wrote:
>>> 16.08.2019 4:01, John Snow wrote:
>>>>
>>>>
>>>> On 7/19/19 12:30 PM, Andrey Shinkevich wrote:
>>>>> To synchronize the time when QEMU is running longer under the Valgrind,
>>>>> increase the sleeping time in the test 247.
>>>>>
>>>>> Signed-off-by: Andrey Shinkevich <address@hidden>
>>>>> Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>
>>>>> ---
>>>>>    tests/qemu-iotests/247 | 6 +++++-
>>>>>    1 file changed, 5 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/tests/qemu-iotests/247 b/tests/qemu-iotests/247
>>>>> index 546a794..c853b73 100755
>>>>> --- a/tests/qemu-iotests/247
>>>>> +++ b/tests/qemu-iotests/247
>>>>> @@ -57,7 +57,11 @@ TEST_IMG="$TEST_IMG.4" _make_test_img $size
>>>>>    {"execute":"block-commit",
>>>>>     "arguments":{"device":"format-4", "top-node": "format-2", 
>>>>> "base-node":"format-0", "job-id":"job0"}}
>>>>>    EOF
>>>>> -sleep 1
>>>>> +if [ "${VALGRIND_QEMU}" == "y" ]; then
>>>>> +    sleep 10
>>>>> +else
>>>>> +    sleep 1
>>>>> +fi
>>>>>    echo '{"execute":"quit"}'
>>>>>    ) | $QEMU -qmp stdio -nographic -nodefaults \
>>>>>        -blockdev 
>>>>> file,node-name=file-0,filename=$TEST_IMG.0,auto-read-only=on \
>>>>>
>>>>
>>>> This makes me nervous, though. Won't this race terribly? (Wait, why
>>>> doesn't it race already?)
>>>>
>>>
>>> Hmm, however it works somehow. I'm afraid that everything with "sleep" is 
>>> definitely racy..
>>> Or what do you mean?
>>>
>>
>> Right -- anything with a sleep is already at risk for racing.
>>
>> What I am picking up on here is that with valgrind, there is an even
>> greater computational overhead that's much harder to predict, so I was
>> wondering how these values were determined.
>>
> 
> I just followed the trend and extended the sleeping time with a grater 
> tolerance so that the test could pass on systems where the 'sleep 1' 
> command helps to pass without Valgrind. We could rewrite the test 247 in 
> Python in a separate series, shall we?
> 

If you have the time, but I don't think anyone will require it for this
series.

Just reviewing "out loud." I'll look at V6 soon.

--js