diff mbox series

[1/4] selftests/cgroup: fix clang build failures for abs() calls

Message ID 20240503035105.93280-2-jhubbard@nvidia.com (mailing list archive)
State New
Headers show
Series selftests/cgroups: fix clang build failures, warnings | expand

Commit Message

John Hubbard May 3, 2024, 3:51 a.m. UTC
First of all, in order to build with clang at all, one must first apply
Valentin Obst's build fix for LLVM [1]. Once that is done, then when
building with clang, via:

    make LLVM=1 -C tools/testing/selftests

...clang is pickier than gcc, about which version of abs(3) to call,
depending on the argument type:

   int abs(int j);
   long labs(long j);
   long long llabs(long long j);

...and this is causing both build failures and warnings, when running:

    make LLVM=1 -C tools/testing/selftests

Fix this by calling labs() in value_close(), because the arguments are
unambiguously "long" type.

[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 tools/testing/selftests/cgroup/cgroup_util.h | 2 +-
 tools/testing/selftests/cgroup/test_kmem.c   | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

Comments

Roman Gushchin May 3, 2024, 5:53 p.m. UTC | #1
On Thu, May 02, 2024 at 08:51:02PM -0700, John Hubbard wrote:
> First of all, in order to build with clang at all, one must first apply
> Valentin Obst's build fix for LLVM [1]. Once that is done, then when
> building with clang, via:
> 
>     make LLVM=1 -C tools/testing/selftests
> 
> ...clang is pickier than gcc, about which version of abs(3) to call,
> depending on the argument type:
> 
>    int abs(int j);
>    long labs(long j);
>    long long llabs(long long j);
> 
> ...and this is causing both build failures and warnings, when running:
> 
>     make LLVM=1 -C tools/testing/selftests
> 
> Fix this by calling labs() in value_close(), because the arguments are
> unambiguously "long" type.
> 
> [1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/
> 
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>

Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>

Thanks!
diff mbox series

Patch

diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h
index 1df7f202214a..239633e936df 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.h
+++ b/tools/testing/selftests/cgroup/cgroup_util.h
@@ -18,7 +18,7 @@ 
  */
 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 c82f974b85c9..d21d3d280ca2 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 = anon + file + kernel + 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);
@@ -380,7 +380,7 @@  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