[PATCH v2 1/2] selftests: cgroup: Use values_close_report in test_memcontrol

[Sebastian Chlad <sebastianchlad@gmail.com>]

Convert the terminal tolerance checks in test_memcontrol to
values_close_report() so that a failure prints the observed and
expected values instead of failing silently. Also report the
"memory.current < size" check in alloc_anon_50M_check().

values_close() is kept where it is used as a loop or retry condition
(waiting for usage to settle in test_memcg_protection(), reclaim_until(),
the reclaim retry loop and the socket test), since a mismatch there is
expected and reporting it would print spurious failures.

Assisted-by: claude-opus-5-5
Signed-off-by: Sebastian Chlad <sebastian.chlad@suse.com>
---
 .../selftests/cgroup/test_memcontrol.c        | 25 +++++++++++--------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index 0ed82347044e..8882c7faeb32 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -200,17 +200,20 @@ static int alloc_anon_50M_check(const char *cgroup, void *arg)
 		return -1;
 
 	current = cg_read_long(cgroup, "memory.current");
-	if (current < size)
+	if (current < size) {
+		fprintf(stderr, "memory.current %ld < expected %zu\n",
+			current, size);
 		goto cleanup;
+	}
 
-	if (!values_close(size, current, 3))
+	if (!values_close_report(current, size, 3))
 		goto cleanup;
 
 	anon = cg_read_key_long(cgroup, "memory.stat", "anon ");
 	if (anon < 0)
 		goto cleanup;
 
-	if (!values_close(anon, current, 3))
+	if (!values_close_report(anon, current, 3))
 		goto cleanup;
 
 	ret = 0;
@@ -241,7 +244,7 @@ static int alloc_pagecache_50M_check(const char *cgroup, void *arg)
 	if (file < 0)
 		goto cleanup;
 
-	if (!values_close(file, current, 10))
+	if (!values_close_report(file, current, 10))
 		goto cleanup;
 
 	ret = 0;
@@ -578,16 +581,16 @@ static int test_memcg_protection(const char *root, bool min)
 	if (cg_run(parent[2], alloc_anon, (void *)MB(148)))
 		goto cleanup;
 
-	if (!values_close(cg_read_long(parent[1], "memory.current"), MB(50), 3))
+	if (!values_close_report(cg_read_long(parent[1], "memory.current"), MB(50), 3))
 		goto cleanup;
 
 	for (i = 0; i < ARRAY_SIZE(children); i++)
 		c[i] = cg_read_long(children[i], "memory.current");
 
-	if (!values_close(c[0], MB(29), 15))
+	if (!values_close_report(c[0], MB(29), 15))
 		goto cleanup;
 
-	if (!values_close(c[1], MB(21), 20))
+	if (!values_close_report(c[1], MB(21), 20))
 		goto cleanup;
 
 	if (c[3] != 0)
@@ -603,7 +606,7 @@ static int test_memcg_protection(const char *root, bool min)
 	}
 
 	current = min ? MB(50) : MB(30);
-	if (!values_close(cg_read_long(parent[1], "memory.current"), current, 3))
+	if (!values_close_report(cg_read_long(parent[1], "memory.current"), current, 3))
 		goto cleanup;
 
 	if (!reclaim_until(children[0], MB(10)))
@@ -691,7 +694,7 @@ static int alloc_pagecache_max_30M(const char *cgroup, void *arg)
 		goto cleanup;
 
 	current = cg_read_long(cgroup, "memory.current");
-	if (!values_close(current, MB(30), 5))
+	if (!values_close_report(current, MB(30), 5))
 		goto cleanup;
 
 	ret = 0;
@@ -1006,12 +1009,12 @@ static int alloc_anon_50M_check_swap(const char *cgroup, void *arg)
 		return -1;
 
 	mem_current = cg_read_long(cgroup, "memory.current");
-	if (!mem_current || !values_close(mem_current, mem_max, 3))
+	if (!mem_current || !values_close_report(mem_current, mem_max, 3))
 		goto cleanup;
 
 	swap_current = cg_read_long(cgroup, "memory.swap.current");
 	if (!swap_current ||
-	    !values_close(mem_current + swap_current, size, 3))
+	    !values_close_report(mem_current + swap_current, size, 3))
 		goto cleanup;
 
 	ret = 0;
-- 
2.51.0