[PATCH v3 1/3] sched/fair: Remove unused task_numa_migrate return value

[Chuyi Zhou]

Initial NUMA Balancing implementation used the return value of
task_numa_migrate() to retry NUMA Balancing in commit 6b9a7460b6ba
("sched/numa: Retry migration of tasks to CPU on a preferred node") however
in the same series[1], Mel also included an optimization from Rik which
retried NUMA Balancing periodically irrespective the return value from
task_numa_migrate() in commit 2739d3eef3a9 ("sched/numa: Retry
task_numa_migrate() periodically").

The return value of task_numa_migrate now is unused, remove it.

[1] https://lore.kernel.org/all/1381141781-10992-34-git-send-email-mgorman@xxxxxxx/

Reviewed-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
Reviewed-by: Madadi Vineeth Reddy <vineethr@xxxxxxxxxxxxx>
Signed-off-by: Chuyi Zhou <zhouchuyi@xxxxxxxxxxxxx>
---
 kernel/sched/fair.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d5127d9beaea..f544012b9320 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2486,7 +2486,7 @@ static void task_numa_find_cpu(struct task_numa_env *env,
 	}
 }
 
-static int task_numa_migrate(struct task_struct *p)
+static void task_numa_migrate(struct task_struct *p)
 {
 	struct task_numa_env env = {
 		.p = p,
@@ -2531,7 +2531,7 @@ static int task_numa_migrate(struct task_struct *p)
 	 */
 	if (unlikely(!sd)) {
 		sched_setnuma(p, task_node(p));
-		return -EINVAL;
+		return;
 	}
 
 	env.dst_nid = p->numa_preferred_nid;
@@ -2600,7 +2600,7 @@ static int task_numa_migrate(struct task_struct *p)
 	/* No better CPU than the current one was found. */
 	if (env.best_cpu == -1) {
 		trace_sched_stick_numa(p, env.src_cpu, NULL, -1);
-		return -EAGAIN;
+		return;
 	}
 
 	best_rq = cpu_rq(env.best_cpu);
@@ -2609,7 +2609,7 @@ static int task_numa_migrate(struct task_struct *p)
 		WRITE_ONCE(best_rq->numa_migrate_on, 0);
 		if (ret != 0)
 			trace_sched_stick_numa(p, env.src_cpu, NULL, env.best_cpu);
-		return ret;
+		return;
 	}
 
 	ret = migrate_swap(p, env.best_task, env.best_cpu, env.src_cpu);
@@ -2618,7 +2618,6 @@ static int task_numa_migrate(struct task_struct *p)
 	if (ret != 0)
 		trace_sched_stick_numa(p, env.src_cpu, env.best_task, env.best_cpu);
 	put_task_struct(env.best_task);
-	return ret;
 }
 
 /* Attempt to migrate a task to a CPU on the preferred node. */
-- 
2.20.1