[PATCH mm-new v2] mm/khugepaged: Factor out common logic in [scan,alloc]_sleep_millisecs_store()

[Leon Hwang <leon.hwang@linux.dev>]

Both scan_sleep_millisecs_store() and alloc_sleep_millisecs_store()
perform the same operations: parse the input value, update their
respective sleep interval, reset khugepaged_sleep_expire, and wake up
the khugepaged thread.

Factor out this duplicated logic into a helper function
__sleep_millisecs_store(), and simplify both store functions.

No functional change intended.

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
---
v1 -> v2:
  - Simplify callsites of __sleep_millisecs_store() (per Lorenzo).
  - Collect Reviewed-by from Lorenzo, Zi and Lance - thanks!
  - https://lore.kernel.org/linux-mm/20251020115350.8175-1-leon.hwang@linux.dev/

 mm/khugepaged.c | 27 +++++++++++----------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 6f2ae2238b5b..5b7276bc14b1 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -129,9 +129,8 @@ static ssize_t scan_sleep_millisecs_show(struct kobject *kobj,
 	return sysfs_emit(buf, "%u\n", khugepaged_scan_sleep_millisecs);
 }

-static ssize_t scan_sleep_millisecs_store(struct kobject *kobj,
-					  struct kobj_attribute *attr,
-					  const char *buf, size_t count)
+static ssize_t __sleep_millisecs_store(const char *buf, size_t count,
+				       unsigned int *millisecs)
 {
 	unsigned int msecs;
 	int err;
@@ -140,12 +139,19 @@ static ssize_t scan_sleep_millisecs_store(struct kobject *kobj,
 	if (err)
 		return -EINVAL;

-	khugepaged_scan_sleep_millisecs = msecs;
+	*millisecs = msecs;
 	khugepaged_sleep_expire = 0;
 	wake_up_interruptible(&khugepaged_wait);

 	return count;
 }
+
+static ssize_t scan_sleep_millisecs_store(struct kobject *kobj,
+					  struct kobj_attribute *attr,
+					  const char *buf, size_t count)
+{
+	return __sleep_millisecs_store(buf, count, &khugepaged_scan_sleep_millisecs);
+}
 static struct kobj_attribute scan_sleep_millisecs_attr =
 	__ATTR_RW(scan_sleep_millisecs);

@@ -160,18 +166,7 @@ static ssize_t alloc_sleep_millisecs_store(struct kobject *kobj,
 					   struct kobj_attribute *attr,
 					   const char *buf, size_t count)
 {
-	unsigned int msecs;
-	int err;
-
-	err = kstrtouint(buf, 10, &msecs);
-	if (err)
-		return -EINVAL;
-
-	khugepaged_alloc_sleep_millisecs = msecs;
-	khugepaged_sleep_expire = 0;
-	wake_up_interruptible(&khugepaged_wait);
-
-	return count;
+	return __sleep_millisecs_store(buf, count, &khugepaged_alloc_sleep_millisecs);
 }
 static struct kobj_attribute alloc_sleep_millisecs_attr =
 	__ATTR_RW(alloc_sleep_millisecs);
--
2.51.0