[LTP] [PATCH 2/6] sched_football: Use atomic for ball

John Stultz jstultz@google.com
Wed Apr 24 00:57:59 CEST 2024


Use atomic type for the ball value, as we don't have any locking
going on.

Cc: kernel-team@android.com
Cc: Darren Hart <darren@os.amperecomputing.com>
Signed-off-by: John Stultz <jstultz@google.com>
---
 testcases/realtime/func/sched_football/sched_football.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/testcases/realtime/func/sched_football/sched_football.c b/testcases/realtime/func/sched_football/sched_football.c
index 1e205219d..359c96703 100644
--- a/testcases/realtime/func/sched_football/sched_football.c
+++ b/testcases/realtime/func/sched_football/sched_football.c
@@ -71,7 +71,7 @@
 #define DEF_GAME_LENGTH 5
 
 /* Here's the position of the ball */
-volatile int the_ball;
+static atomic_t the_ball;
 
 static int players_per_team = 0;
 static int game_length = DEF_GAME_LENGTH;
@@ -122,7 +122,7 @@ void *thread_offense(void *arg)
 {
 	atomic_inc(&players_ready);
 	while (1) {
-		the_ball++;	/* move the ball ahead one yard */
+		atomic_inc(&the_ball);	/* move the ball ahead one yard */
 	}
 	return NULL;
 }
@@ -138,16 +138,16 @@ int referee(int game_length)
 	now = start;
 
 	/* Start the game! */
-	the_ball = 0;
+	atomic_set(0, &the_ball);
 
 	/* Watch the game */
 	while ((now.tv_sec - start.tv_sec) < game_length) {
 		sleep(1);
 		gettimeofday(&now, NULL);
 	}
+	final_ball = atomic_get(&the_ball);
 	/* Blow the whistle */
 	printf("Game Over!\n");
-	final_ball = the_ball;
 	printf("Final ball position: %d\n", final_ball);
 	return final_ball != 0;
 }
-- 
2.44.0.769.g3c40516874-goog



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