[PATCH] Increase timeout for tests and syntax-check

Daniel Henrique Barboza danielhb413 at gmail.com
Fri Jan 29 13:33:32 UTC 2021

On 1/29/21 10:04 AM, Michal Privoznik wrote:
> On 1/29/21 1:30 PM, Daniel Henrique Barboza wrote:
>> On 1/27/21 2:59 PM, Michal Privoznik wrote:
>>> Since we've switched to meson our tests run with a timeout (meson
>>> uses 30 seconds as the default). However, not every machine that
>>> builds libvirt is fast enough to run every test under 30 seconds
>>> (each test binary has its own timeout, but still). For instance
>>> when building a package for distro on a farm that's under load.
>>> Or on a generally slow ARM hardware. While each developer can
>>> tune their command line for building by adding
>>> --timeout-multiplier=10, this is hard to do for aforementioned
>>> build farms.
>>> It's time to admit that not everybody has the latest, top shelf
>>> CPU and increase the timeout.
>>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>>> ---
>> This sure will help these build farms environments, but what about the cases
>> where an actual timeout means that there is something wrong with the code?
>> E.g. commits 46d88d8dba56 and 2ba0b7497ce7 were only possible because I was
>> seeing tests timing out in Power hosts when the 30 sec timeout was being
>> enforced.
>> A 120 second default timeout for the majority of the test cases is a long time.
>> virschematest in this laptop I use takes 2.5 sec to complete. If I do something
>> wrong in the code and now the test is now 4 times slower (10 sec) I will not be
>> able to detect it (I'll need to start keeping track or something). 
> With 30 second timeout you won't detect that either. Using timeout as an indicator of test failure is wrong IMO. And if I were not lazy and fixed 'check-access' test suite then we would see instantly what tests are accessing paths in the host (=> depend on host configuration).

30 sec is too long for most tests :)

Let's put it this way: I don't think most of us keeps track of how much a
certain test takes to complete during our dev, and the 30 sec timeout is
a marker to see if we messed up or not. A 120 timeout is too extreme for
my dev env (and I believe most if not all of us can run the test suit without
any problems during development).

All that said, I just ran 'ninja -C build test' and verified that we don't provide
a total run time for all tests. We provide the time taken for all 306 tests, but
not a total. If we change the script to output the total time taken to run all
tests in the test suit, in a successful run (i.e. no failed tests), then I wouldn't
mind the timeout increase. I can run the test suit in master, get the total time
taken, do some coding, run again, compare the new total. This comparison will give
me a hint of whether something went too wrong, then I can compare the numbers myself
to see what happened. In this case I wouldn't mind removing all test timeouts or
increasing the timeout to help the distros or what have you.



>> You'll have to
>> run the test suit on your RasPi 2B to see that something went wrong because the
>> timeout is better tuned to your RasPI than this laptop, but then the code is already
>> upstream.
> So should we make timeouts shorter then? Why is 30 seconds sweet spot?
>> And the tests will get more complex and will naturally take longer to complete.
>> Eventually this timeout might no be enough. Increase the timeout again?
> Sure, why not? We adapt to newer gcc/clang/$whatever, why not timeout?
> Michal

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