From: Harish <harish@linux.ibm.com>
To: mpe@ellerman.id.au
Cc: srikar@linux.vnet.ibm.com, kamalesh@linux.vnet.ibm.com,
shiganta@in.ibm.com, sandipan@linux.ibm.com,
Harish <harish@linux.ibm.com>,
linuxppc-dev@lists.ozlabs.org
Subject: [PATCH] selftests: powerpc: Fix online CPU selection
Date: Mon, 8 Jun 2020 22:22:26 +0530 [thread overview]
Message-ID: <20200608165226.516985-1-harish@linux.ibm.com> (raw)
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 <shiganta@in.ibm.com>
Signed-off-by: Harish <harish@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
.../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
next reply other threads:[~2020-06-08 16:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-08 16:52 Harish [this message]
-- strict thread matches above, loose matches on Subject: below --
2020-06-08 14:42 [PATCH] selftests: powerpc: Fix online CPU selection Sandipan Das
2020-06-08 15:05 ` Kamalesh Babulal
2020-06-09 6:12 ` Sandipan Das
2020-06-09 6:20 ` Sandipan Das
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