mm/damon/core: make damon_stop() never fail

damon_stop() has no reason to fail.  It returns an error code only for
possible future changes that can make it fail.  Such a change has not been
made yet, and this only makes the error handling complicated and
confusing.  Ensure it returns no error.

Link: https://lore.kernel.org/20260706140628.87414-4-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 6 insertions, 15 deletions

diff --git a/mm/damon/core.c b/mm/damon/core.c
index d89a7f2faf35..84e400aa4e82 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -1926,10 +1926,8 @@ int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive)
 /*
  * __damon_stop() - Stops monitoring of a given context.
  * @ctx:	monitoring context
- *
- * Return: 0 on success, negative error code otherwise.
  */
-static int __damon_stop(struct damon_ctx *ctx)
+static void __damon_stop(struct damon_ctx *ctx)
 {
 	struct task_struct *tsk;
 
@@ -1939,31 +1937,24 @@ static int __damon_stop(struct damon_ctx *ctx)
 		get_task_struct(tsk);
 		mutex_unlock(&ctx->kdamond_lock);
 		kthread_stop_put(tsk);
-		return 0;
+		return;
 	}
 	mutex_unlock(&ctx->kdamond_lock);
-
-	return -EPERM;
 }
 
 /**
  * damon_stop() - Stops the monitorings for a given group of contexts.
  * @ctxs:	an array of the pointers for contexts to stop monitoring
  * @nr_ctxs:	size of @ctxs
- *
- * Return: 0 on success, negative error code otherwise.
  */
 int damon_stop(struct damon_ctx **ctxs, int nr_ctxs)
 {
-	int i, err = 0;
+	int i;
 
-	for (i = 0; i < nr_ctxs; i++) {
+	for (i = 0; i < nr_ctxs; i++)
 		/* nr_running_ctxs is decremented in kdamond_fn */
-		err = __damon_stop(ctxs[i]);
-		if (err)
-			break;
-	}
-	return err;
+		__damon_stop(ctxs[i]);
+	return 0;
 }
 
 /**