[LTP] [PATCH v2] 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: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Edward Liaw <edliaw@google.com>
---
 .../kernel/sched/cfs-scheduler/starvation.c   | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/testcases/kernel/sched/cfs-scheduler/starvation.c b/testcases/kernel/sched/cfs-scheduler/starvation.c
index eb9fd6ff5..0fd45e281 100644
--- a/testcases/kernel/sched/cfs-scheduler/starvation.c
+++ b/testcases/kernel/sched/cfs-scheduler/starvation.c
@@ -49,12 +49,27 @@ 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 */
+	TST_EXP_PASS(sched_getaffinity(0, sizeof(mask), &mask));
 
-	TST_EXP_POSITIVE(sched_setaffinity(0, sizeof(mask), &mask));
+	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_EXP_PASS(sched_setaffinity(0, sizeof(mask), &mask));
+
+	tst_res(TINFO, "Set affinity to CPU %d", cpu);
 
 	if (tst_parse_long(str_loop, &loop, 1, LONG_MAX))
 		tst_brk(TBROK, "Invalid number of loop number '%s'", str_loop);
-- 
2.45.1.467.gbab1589fc0-goog