mm/khugepaged.c: replace barrier() with READ_ONCE() for a selective variable

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.

Link: https://lkml.kernel.org/r/20210323092730.247583-1-yanfei.xu@windriver.com
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Yanfei Xu 2021-05-04 18:34:12 -07:00 committed by Linus Torvalds
parent a44f89dc6c
commit 89dc6a9682

View File

@ -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) {