cpu.max selftests (both the normal one and the nested one) test the working of throttling by setting up cpu.max, running a cpu hog process for a specified duration, and comparing usage_usec as reported by cpu.stat with the duration of the cpu hog: they should be far enough.
Currently, this is done by using values_close, which has two problems: 1. Semantic: values_close is used with an error percentage of 95%, which one will not expect on seeing "values close". The intent it's actually going for is "values far". 2. Accuracy: the tests can pass even if usage_usec is upto around double the expected amount. That's too high of a margin for usage_usec. Overall, this patchset improves the readability and accuracy of the cpu.max tests. Signed-off-by: Shashank Balaji <[email protected]> --- Shashank Balaji (2): selftests/cgroup: rename `expected` to `duration` in cpu.max tests selftests/cgroup: better bound in cpu.max tests tools/testing/selftests/cgroup/test_cpu.c | 42 ++++++++++++++++++------------- 1 file changed, 24 insertions(+), 18 deletions(-) --- base-commit: 66701750d5565c574af42bef0b789ce0203e3071 change-id: 20250227-kselftest-cgroup-fix-cpu-max-56619928e99b Best regards, -- Shashank Balaji <[email protected]>
