[PATCH] selftests: powerpc: Fix online CPU selection
From: Harish <hidden>
Date: 2020-06-08 16:54:32
Subsystem:
kernel selftest framework, the rest · Maintainers:
Shuah Khan, Shuah Khan, Linus Torvalds
On systems with large number of cpus, test fails trying to set affinity by calling sched_setaffinity() with smaller size for cpuset. This patch fixes it by making sure that the size of allocated cpu set is dependent on the number of CPUs as reported by get_nprocs(). Reported-by: Shirisha Ganta <redacted> Signed-off-by: Harish <redacted> Signed-off-by: Sandipan Das <redacted> --- .../powerpc/benchmarks/context_switch.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/powerpc/benchmarks/context_switch.c b/tools/testing/selftests/powerpc/benchmarks/context_switch.c
index a2e8c9da7fa5..de6c49d6f88f 100644
--- a/tools/testing/selftests/powerpc/benchmarks/context_switch.c
+++ b/tools/testing/selftests/powerpc/benchmarks/context_switch.c@@ -19,6 +19,7 @@ #include <limits.h> #include <sys/time.h> #include <sys/syscall.h> +#include <sys/sysinfo.h> #include <sys/types.h> #include <sys/shm.h> #include <linux/futex.h>
@@ -104,8 +105,9 @@ static void start_thread_on(void *(*fn)(void *), void *arg, unsigned long cpu) static void start_process_on(void *(*fn)(void *), void *arg, unsigned long cpu) { - int pid; - cpu_set_t cpuset; + int pid, ncpus; + cpu_set_t *cpuset; + size_t size; pid = fork(); if (pid == -1) {
@@ -116,12 +118,16 @@ static void start_process_on(void *(*fn)(void *), void *arg, unsigned long cpu) if (pid) return; - CPU_ZERO(&cpuset); - CPU_SET(cpu, &cpuset); + size = CPU_ALLOC_SIZE(ncpus); + ncpus = get_nprocs(); + cpuset = CPU_ALLOC(ncpus); + CPU_ZERO_S(size, cpuset); + CPU_SET_S(cpu, size, cpuset); - if (sched_setaffinity(0, sizeof(cpuset), &cpuset)) { + if (sched_setaffinity(0, size, cpuset)) { perror("sched_setaffinity"); - exit(1); + CPU_FREE(cpuset); + exit(-1); } fn(arg);
--
2.24.1