[LTP] [PATCH v5 2/2] sched/starvation: Choose from available cpus

[Edward Liaw]

From: Edward Liaw via ltp <ltp@lists.linux.it>

Use the first available cpu in the sched_getaffinity set.

This test was failing as a 32bit test for some arm architectures where
cpu 0 does not support 32bit applications.

Reviewed-by: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: Edward Liaw <edliaw@google.com>
---
 .../kernel/sched/cfs-scheduler/starvation.c    | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/testcases/kernel/sched/cfs-scheduler/starvation.c b/testcases/kernel/sched/cfs-scheduler/starvation.c
index c845af849..9ac388fdc 100644
--- a/testcases/kernel/sched/cfs-scheduler/starvation.c
+++ b/testcases/kernel/sched/cfs-scheduler/starvation.c
@@ -49,10 +49,26 @@ again:
 static void setup(void)
 {
 	cpu_set_t mask;
+	int cpu = 0;
+	long ncpus = tst_ncpus_conf();
 
 	CPU_ZERO(&mask);
 
-	CPU_SET(0, &mask);
+	/* Restrict test to a single cpu */
+	if (sched_getaffinity(0, sizeof(mask), &mask) < 0)
+		tst_brk(TBROK | TERRNO, "sched_getaffinity() failed");
+
+	if (CPU_COUNT(&mask) == 0)
+		tst_brk(TBROK, "No cpus available");
+
+	while (CPU_ISSET(cpu, &mask) == 0 && cpu < ncpus)
+		cpu++;
+
+	CPU_ZERO(&mask);
+
+	CPU_SET(cpu, &mask);
+
+	tst_res(TINFO, "Setting affinity to CPU %d", cpu);
 
 	if (sched_setaffinity(0, sizeof(mask), &mask) < 0)
 		tst_brk(TBROK | TERRNO, "sched_setaffinity() failed");
-- 
2.45.2.627.g7a2c4fd464-goog