• Mark Brown's avatar
    kselftest/arm64: Check that all children are producing output in fp-stress · 3a38ef2b
    Mark Brown authored
    
    
    Currently we don't have an explicit check that when it's been a second
    since we have seen output produced from the test programs starting up that
    means all of them are running and we should start both sending signals and
    timing out. This is not reliable, especially on very heavily loaded systems
    where the test programs might take longer than a second to run.
    
    We do skip sending signals to children that have not produced output yet
    so we won't cause them to exit unexpectedly by sending a signal but this
    can create confusion when interpreting output, for example appearing to
    show the tests running for less time than expected or appearing to show
    missed signal deliveries. Avoid issues by explicitly checking that we have
    seen output from all the child processes before we start sending signals
    or counting test run time.
    
    This is especially likely on virtual platforms with large numbers of vector
    lengths supported since the platforms are slow and there will be a lot of
    tasks per CPU.
    Signed-off-by: default avatarMark Brown <broonie@kernel.org>
    Link: https://lore.kernel.org/r/20221017144553.773176-2-broonie@kernel.org
    
    Signed-off-by: default avatarWill Deacon <will@kernel.org>
    3a38ef2b
fp-stress.c 12.4 KB