[LTP] [PATCH] sched_rr_get_interval: run tests under SCHED_RR policy

[Jan Stancek]

Man page says:
 The specified process should be running under the SCHED_RR
 scheduling policy.

sched_rr_get_interval_1-1 can rarely fail if run as
SCHED_OTHER, because time quantum calculated/returned by
get_rr_interval_fair() can change between two calls.
For example it depends on number of running tasks on runq.

This patch sets sched policy to SCHED_RR.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
---
 .../conformance/interfaces/sched_rr_get_interval/1-1.c | 15 ++++++++++++---
 .../conformance/interfaces/sched_rr_get_interval/2-1.c | 15 ++++++++++++---
 .../conformance/interfaces/sched_rr_get_interval/3-1.c | 18 +++++++++++++-----
 3 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/1-1.c b/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/1-1.c
index 28ef9eba6ebe..e7a1e846e5a3 100644
--- a/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/1-1.c
+++ b/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/1-1.c
@@ -11,12 +11,13 @@
  * Test that the current execution time limit is returned for the calling
  * process when pid = 0.
  */
-#include <stdio.h>
-#include <sched.h>
 #include <errno.h>
+#include <sched.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
 #include <unistd.h>
 #include "posixtest.h"
-#include <time.h>
 
 int main(void)
 {
@@ -25,6 +26,14 @@ int main(void)
 	struct timespec interval1;
 	int result0 = -1;
 	int result1 = -1;
+	struct sched_param param;
+
+	param.sched_priority = sched_get_priority_min(SCHED_RR);
+	if (sched_setscheduler(0, SCHED_RR, &param) == -1) {
+		printf("sched_setscheduler failed: %d (%s)\n",
+			errno, strerror(errno));
+		return PTS_UNRESOLVED;
+	}
 
 	interval0.tv_sec = -1;
 	interval0.tv_nsec = -1;
diff --git a/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/2-1.c b/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/2-1.c
index 0b29586ab3b5..5dedf1f6e7ff 100644
--- a/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/2-1.c
+++ b/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/2-1.c
@@ -10,16 +10,25 @@
  *
  * sched_rr_get_interval() returns 0 on success.
  */
-#include <stdio.h>
-#include <sched.h>
 #include <errno.h>
-#include "posixtest.h"
+#include <sched.h>
+#include <stdio.h>
+#include <string.h>
 #include <time.h>
+#include "posixtest.h"
 
 int main(void)
 {
 	struct timespec interval;
 	int result = -2;
+	struct sched_param param;
+
+	param.sched_priority = sched_get_priority_min(SCHED_RR);
+	if (sched_setscheduler(0, SCHED_RR, &param) == -1) {
+		printf("sched_setscheduler failed: %d (%s)\n",
+			errno, strerror(errno));
+		return PTS_UNRESOLVED;
+	}
 
 	interval.tv_sec = -1;
 	interval.tv_nsec = -1;
diff --git a/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/3-1.c b/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/3-1.c
index 75fc5a0a5463..ee421a1973bc 100644
--- a/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/3-1.c
+++ b/testcases/open_posix_testsuite/conformance/interfaces/sched_rr_get_interval/3-1.c
@@ -13,20 +13,28 @@
  * The test create a child process which exit immediately and call
  * sched_rr_get_interval with the pid of defunct child.
  */
-#include <stdio.h>
-#include <sched.h>
 #include <errno.h>
-#include <unistd.h>
+#include <sched.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
 #include <sys/wait.h>
 #include "posixtest.h"
-#include <time.h>
 
 int main(void)
 {
-
 	struct timespec interval;
 	int result = -2, child_pid, stat_loc;
+	struct sched_param param;
+
+	param.sched_priority = sched_get_priority_min(SCHED_RR);
+	if (sched_setscheduler(0, SCHED_RR, &param) == -1) {
+		printf("sched_setscheduler failed: %d (%s)\n",
+			errno, strerror(errno));
+		return PTS_UNRESOLVED;
+	}
 
 	/* Create a child process which exit immediately */
 	child_pid = fork();
-- 
1.8.3.1