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-v1-1-2f9ed7d1c...
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(-)
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