[PATCH] khugepaged: Raplace barrier() with READ_ONCE() for a selective variable
From: yanfei . xu
Date: Tue Mar 23 2021 - 05:28:33 EST
From: Yanfei Xu <yanfei.xu@xxxxxxxxxxxxx>
READ_ONCE() is more selective and lightweight. It is more appropriate that
using a READ_ONCE() for the certain variable to prevent the compiler from
reordering.
Signed-off-by: Yanfei Xu <yanfei.xu@xxxxxxxxxxxxx>
---
mm/khugepaged.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index b81521dfbb1a..034d05a26cb0 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2202,11 +2202,9 @@ static void khugepaged_do_scan(void)
{
struct page *hpage = NULL;
unsigned int progress = 0, pass_through_head = 0;
- unsigned int pages = khugepaged_pages_to_scan;
+ unsigned int pages = READ_ONCE(khugepaged_pages_to_scan);
bool wait = true;
- barrier(); /* write khugepaged_pages_to_scan to local stack */
-
lru_add_drain_all();
while (progress < pages) {
--
2.27.0