From: Sebastian Chlad Date: Wed, 15 Oct 2025 10:33:56 +0000 (+0200) Subject: selftests: cgroup: add values_close_report helper X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3f9c60f4d3cc3e7f4dd7cac05011ea06d512050f;p=users%2Fhch%2Fmisc.git selftests: cgroup: add values_close_report helper Some cgroup selftests, such as test_cpu, occasionally fail by a very small margin and if run in the CI context, it is useful to have detailed diagnostic output to understand the deviation. Introduce a values_close_report() helper which performs the same comparison as values_close(), but prints detailed information when the values differ beyond the allowed tolerance. Signed-off-by: Sebastian Chlad Signed-off-by: Tejun Heo --- diff --git a/tools/testing/selftests/cgroup/lib/include/cgroup_util.h b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h index 9dc90a1b386d..7ab2824ed7b5 100644 --- a/tools/testing/selftests/cgroup/lib/include/cgroup_util.h +++ b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h @@ -25,6 +25,26 @@ static inline int values_close(long a, long b, int err) return labs(a - b) <= (a + b) / 100 * err; } +/* + * Checks if two given values differ by less than err% of their sum and assert + * with detailed debug info if not. + */ +static inline int values_close_report(long a, long b, int err) +{ + long diff = labs(a - b); + long limit = (a + b) / 100 * err; + double actual_err = (a + b) ? (100.0 * diff / (a + b)) : 0.0; + int close = diff <= limit; + + if (!close) + fprintf(stderr, + "[FAIL] actual=%ld expected=%ld | diff=%ld | limit=%ld | " + "tolerance=%d%% | actual_error=%.2f%%\n", + a, b, diff, limit, err, actual_err); + + return close; +} + extern ssize_t read_text(const char *path, char *buf, size_t max_len); extern ssize_t write_text(const char *path, char *buf, ssize_t len);