linux-kernel - [PATCH mm-new 1/1] mm/khugepaged: Factor out common logic in [scan,alloc]_sleep_millisecs

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Message-ID: <20251020115350.8175-1-leon.hwang@linux.dev>
Date: Mon, 20 Oct 2025 19:53:50 +0800
From: Leon Hwang <leon.hwang@...ux.dev>
To: akpm@...ux-foundation.org,
	david@...hat.com,
	lorenzo.stoakes@...cle.com
Cc: ziy@...dia.com,
	baolin.wang@...ux.alibaba.com,
	Liam.Howlett@...cle.com,
	npache@...hat.com,
	ryan.roberts@....com,
	dev.jain@....com,
	baohua@...nel.org,
	lance.yang@...ux.dev,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Leon Hwang <leon.hwang@...ux.dev>
Subject: [PATCH mm-new 1/1] mm/khugepaged: Factor out common logic in [scan,alloc]_sleep_millisecs_store()

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.

Signed-off-by: Leon Hwang <leon.hwang@...ux.dev>
---
 mm/khugepaged.c | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 0341c3d13e9e..0b7915015e9e 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 +139,21 @@ 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)
+{
+	unsigned int *millisecs = &khugepaged_scan_sleep_millisecs;
+
+	return __sleep_millisecs_store(buf, count, millisecs);
+}
 static struct kobj_attribute scan_sleep_millisecs_attr =
 	__ATTR_RW(scan_sleep_millisecs);
 
@@ -160,18 +168,9 @@ 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;
+	unsigned int *millisecs = &khugepaged_alloc_sleep_millisecs;
 
-	khugepaged_alloc_sleep_millisecs = msecs;
-	khugepaged_sleep_expire = 0;
-	wake_up_interruptible(&khugepaged_wait);
-
-	return count;
+	return __sleep_millisecs_store(buf, count, millisecs);
 }
 static struct kobj_attribute alloc_sleep_millisecs_attr =
 	__ATTR_RW(alloc_sleep_millisecs);
-- 
2.51.0