[LTP] [PATCH V2] syscalls/sched_rr_get_interval: Validate the timeslice

Viresh Kumar
2020-07-06T03:31:53Z

Validate the timespec returned by sched_rr_get_interval() against the
value read from /proc/sys/kernel/sched_rr_timeslice_ms.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
V2:
- Add .tags entry
- check if file is present or not.

.../sched_rr_get_interval01.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/testcases/kernel/syscalls/sched_rr_get_interval/sched_rr_get_interval01.c b/testcases/kernel/syscalls/sched_rr_get_interval/sched_rr_get_interval01.c
index 31d7b5d56a52..0466be36bec0 100644
--- a/testcases/kernel/syscalls/sched_rr_get_interval/sched_rr_get_interval01.c
+++ b/testcases/kernel/syscalls/sched_rr_get_interval/sched_rr_get_interval01.c
@@ -5,11 +5,18 @@
*
* Gets round-robin time quantum by calling sched_rr_get_interval() and
* checks that the value is sane.
+ *
+ * It is also a regression test for kernel
+ * commit 975e155ed873 ("sched/rt: Show the 'sched_rr_timeslice' SCHED_RR
+ * timeslice tuning knob in milliseconds").
*/

#include <sched.h>
#include "tst_timer.h"

+#define PROC_SCHED_RR_TIMESLICE_MS "/proc/sys/kernel/sched_rr_timeslice_ms"
+static int proc_flag;
+
struct tst_ts tp;

static struct test_variants {
@@ -39,6 +46,8 @@ static void setup(void)

if ((sched_setscheduler(0, SCHED_RR, &p)) == -1)
tst_res(TFAIL | TTERRNO, "sched_setscheduler() failed");
+
+ proc_flag = !access(PROC_SCHED_RR_TIMESLICE_MS, F_OK);
}

static void run(void)
@@ -62,6 +71,8 @@ static void run(void)
tst_ts_get_sec(tp), tst_ts_get_nsec(tp));
}

+ if (proc_flag)
+ TST_ASSERT_INT("/proc/sys/kernel/sched_rr_timeslice_ms", tst_ts_to_ms(tp));
}

static struct tst_test test = {
@@ -69,4 +80,8 @@ static struct tst_test test = {
.test_variants = ARRAY_SIZE(variants),
.setup = setup,
.needs_root = 1,
+ .tags = (const struct tst_tag[]) {
+ {"linux-git", "975e155ed873"},
+ {}
+ }
};
--
2.25.0.rc1.19.g042ed3e048af