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

Leon Hwang
2025-10-21T13:45:34Z

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