[PATCH 2/2] selftests: cgroup: use function 'labs()' over 'abs()'

From: Anders Roxell
Date: Fri Nov 05 2021 - 12:25:54 EST


When building selftests/cgroup with clang, the compiler warn about the
function abs() see below:

In file included from test_memcontrol.c:21:
./cgroup_util.h:16:9: warning: absolute value function 'abs' given an argument of type 'long' but has parameter of type 'int' which may cause truncation of value [-Wabsolute-value]
return abs(a - b) <= (a + b) / 100 * err;
^
./cgroup_util.h:16:9: note: use function 'labs' instead
return abs(a - b) <= (a + b) / 100 * err;
^~~
labs

The note indicates what to do, Rework to use the function 'labs()'.

Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
---
tools/testing/selftests/cgroup/cgroup_util.h | 2 +-
tools/testing/selftests/cgroup/test_kmem.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h
index 82e59cdf16e7..76b35d9dffb5 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.h
+++ b/tools/testing/selftests/cgroup/cgroup_util.h
@@ -13,7 +13,7 @@
*/
static inline int values_close(long a, long b, int err)
{
- return abs(a - b) <= (a + b) / 100 * err;
+ return labs(a - b) <= (a + b) / 100 * err;
}

extern int cg_find_unified_root(char *root, size_t len);
diff --git a/tools/testing/selftests/cgroup/test_kmem.c b/tools/testing/selftests/cgroup/test_kmem.c
index 22b31ebb3513..d65bb8fe876a 100644
--- a/tools/testing/selftests/cgroup/test_kmem.c
+++ b/tools/testing/selftests/cgroup/test_kmem.c
@@ -192,7 +192,7 @@ static int test_kmem_memcg_deletion(const char *root)
goto cleanup;

sum = slab + anon + file + kernel_stack + pagetables + percpu + sock;
- if (abs(sum - current) < MAX_VMSTAT_ERROR) {
+ if (labs(sum - current) < MAX_VMSTAT_ERROR) {
ret = KSFT_PASS;
} else {
printf("memory.current = %ld\n", current);
@@ -383,7 +383,7 @@ static int test_percpu_basic(const char *root)
current = cg_read_long(parent, "memory.current");
percpu = cg_read_key_long(parent, "memory.stat", "percpu ");

- if (current > 0 && percpu > 0 && abs(current - percpu) <
+ if (current > 0 && percpu > 0 && labs(current - percpu) <
MAX_VMSTAT_ERROR)
ret = KSFT_PASS;
else
--
2.33.0