[PATCH] selftests: powerpc: Fix online CPU selection
From: Sandipan Das <hidden>
Date: 2020-06-08 14:45:57
The size of the cpu set must be large enough for systems
with a very large number of CPUs. Otherwise, tests which
try to determine the first online CPU by calling
sched_getaffinity() will fail. This makes sure that the
size of the allocated cpu set is dependent on the number
of CPUs as reported by get_nprocs().
Fixes: 3752e453f6ba ("selftests/powerpc: Add tests of PMU EBBs")
Reported-by: Shirisha Ganta <redacted>
Signed-off-by: Sandipan Das <redacted>
---
tools/testing/selftests/powerpc/utils.c | 33 ++++++++++++++++---------
1 file changed, 21 insertions(+), 12 deletions(-)
diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c
index 933678f1ed0a..bb8e402752c0 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c@@ -16,6 +16,7 @@ #include <string.h> #include <sys/ioctl.h> #include <sys/stat.h> +#include <sys/sysinfo.h> #include <sys/types.h> #include <sys/utsname.h> #include <unistd.h>
@@ -88,28 +89,36 @@ void *get_auxv_entry(int type) int pick_online_cpu(void) { - cpu_set_t mask; - int cpu; + int ncpus, cpu = -1; + cpu_set_t *mask; + size_t size; - CPU_ZERO(&mask); + ncpus = get_nprocs(); + size = CPU_ALLOC_SIZE(ncpus); + mask = CPU_ALLOC(ncpus); - if (sched_getaffinity(0, sizeof(mask), &mask)) { + CPU_ZERO_S(size, mask); + + if (sched_getaffinity(0, size, mask)) { perror("sched_getaffinity"); - return -1; + goto done; } /* We prefer a primary thread, but skip 0 */ - for (cpu = 8; cpu < CPU_SETSIZE; cpu += 8) - if (CPU_ISSET(cpu, &mask)) - return cpu; + for (cpu = 8; cpu < ncpus; cpu += 8) + if (CPU_ISSET_S(cpu, size, mask)) + goto done; /* Search for anything, but in reverse */ - for (cpu = CPU_SETSIZE - 1; cpu >= 0; cpu--) - if (CPU_ISSET(cpu, &mask)) - return cpu; + for (cpu = ncpus - 1; cpu >= 0; cpu--) + if (CPU_ISSET_S(cpu, size, mask)) + goto done; printf("No cpus in affinity mask?!\n"); - return -1; + +done: + CPU_FREE(mask); + return cpu; } bool is_ppc64le(void)
--
2.25.1