Commit a7990657 authored by David Vernet's avatar David Vernet Committed by Tejun Heo
Browse files

cgroup: Add test_cpucg_max_nested() testcase 



The cgroup cpu controller selftests have a test_cpucg_max() testcase
that validates the behavior of the cpu.max knob. Let's also add a
testcase that verifies that the behavior works correctly when set on a
nested cgroup.

Signed-off-by: default avatarDavid Vernet <void@manifault.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 889ab811

tools/testing/selftests/cgroup/test_cpu.c

+63 −0
Original line number Diff line number Diff line
@@ -617,6 +617,68 @@ static int test_cpucg_max(const char *root) 
	return ret;

}



/*

 * This test verifies that a process inside of a nested cgroup whose parent

 * group has a cpu.max value set, is properly throttled.

 */

static int test_cpucg_max_nested(const char *root)

{

	int ret = KSFT_FAIL;

	long usage_usec, user_usec;

	long usage_seconds = 1;

	long expected_usage_usec = usage_seconds * USEC_PER_SEC;

	char *parent, *child;



	parent = cg_name(root, "cpucg_parent");

	child = cg_name(parent, "cpucg_child");

	if (!parent || !child)

		goto cleanup;



	if (cg_create(parent))

		goto cleanup;



	if (cg_write(parent, "cgroup.subtree_control", "+cpu"))

		goto cleanup;



	if (cg_create(child))

		goto cleanup;



	if (cg_write(parent, "cpu.max", "1000"))

		goto cleanup;



	struct cpu_hog_func_param param = {

		.nprocs = 1,

		.ts = {

			.tv_sec = usage_seconds,

			.tv_nsec = 0,

		},

		.clock_type = CPU_HOG_CLOCK_WALL,

	};

	if (cg_run(child, hog_cpus_timed, (void *)&param))

		goto cleanup;



	usage_usec = cg_read_key_long(child, "cpu.stat", "usage_usec");

	user_usec = cg_read_key_long(child, "cpu.stat", "user_usec");

	if (user_usec <= 0)

		goto cleanup;



	if (user_usec >= expected_usage_usec)

		goto cleanup;



	if (values_close(usage_usec, expected_usage_usec, 95))

		goto cleanup;



	ret = KSFT_PASS;



cleanup:

	cg_destroy(child);

	free(child);

	cg_destroy(parent);

	free(parent);



	return ret;

}



#define T(x) { x, #x }

struct cpucg_test {

	int (*fn)(const char *root);
@@ -629,6 +691,7 @@ struct cpucg_test { 
	T(test_cpucg_nested_weight_overprovisioned),

	T(test_cpucg_nested_weight_underprovisioned),

	T(test_cpucg_max),

	T(test_cpucg_max_nested),

};

#undef T