Commit 3f9c60f4 authored by Sebastian Chlad's avatar Sebastian Chlad Committed by Tejun Heo
Browse files

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: default avatarSebastian Chlad <sebastian.chlad@suse.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 93a4b36e

tools/testing/selftests/cgroup/lib/include/cgroup_util.h

+20 −0
Original line number Diff line number Diff line
@@ -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);