[LTP] tst_fuzzy_sync01 sporadically fails

Petr Vorel pvorel@suse.cz
Wed Jun 30 12:10:26 CEST 2021


Hi Richie,

> Hello Petr,

> Petr Vorel <pvorel@suse.cz> writes:

> > Hi Richie,

> > ...
> >> > tst_fuzzy_sync01.c:224: TFAIL: acs:1  act:1  art:3  | =:3    -:2999996 +:1   

> >> It looks like the CI machines are too noisy/contended. The avg_dev is
> >> very high. Probably we could relax the dev_ratio threshold to 0.2 or
> >> 0.3. Although we would still get failures occassionally. As this is a
> >> probabalistic test.
> > Test is failing on my laptop, thus haven't enabled it in CI.
> > But maybe it'll be working on it more reliably than my busy machine.

> Is it really that busy? Perhaps we should increase the dev ratio
> threshold. Clearly the deviations from contention are not enough to
> reproduce the races, but are enough to prevent the radomization phase.
I probably did some VM testing or kernel compilation or something.
I'll try to enable for next patchset version it to see how it works on CI.

> > But I'd prefer to wasting time with false positives, thus I guess we should
> > enable only tests which are working reliably.

> >> Could you change the script so that it passes so long as the test
> >> returns TPASS or TFAIL?
> > Well, accepting TFAIL sounds a bit strange to me :).
> > Also next effort will be (at least for shell tests) to compare actual test
> > output. Obviously that will not be straightforward for some tests, which aren't
> > reproducible (avg = 11729ns could be matched by regex, but having more variants
> > of results is kind of special case).

> >> We don't want TBROK, TCONF or no result.
> > FYI in my CI patchset is TCONF accepted. Motivation was to not require root for
> > make test as some tests needed it. Thus TCONF will be a special case, then I
> > guess we could add tst_fuzzy_sync01 accepting TFAIL as a special case.

> At least if we run the tests and look for TPASS or TFAIL, we will catch
> segfaults and similar.

> Also, for fuzzy sync, returning TCONF would be a major error. It should
> run on all systems.
Well, TCONF should be used on places where it's really a configuration issue.
IMHO only TBROK and TFAIL should be a problem. Or is fuzzy sync part somehow
special in this?

Kind regards,
Petr

> > Kind regards,
> > Petr


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