[PATCH v17 19/21] mm/vmscan: use relock for move_pages_to_lru

Alex Shi
2020-07-25T13:00:54Z

From: Hugh Dickins <hughd@google.com>

Use the relock function to replace relocking action. And try to save few
lock times.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: cgroups@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
---
mm/vmscan.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bdb53a678e7e..078a1640ec60 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1854,15 +1854,15 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
enum lru_list lru;

while (!list_empty(list)) {
- struct lruvec *new_lruvec = NULL;
-
page = lru_to_page(list);
VM_BUG_ON_PAGE(PageLRU(page), page);
list_del(&page->lru);
if (unlikely(!page_evictable(page))) {
- spin_unlock_irq(&lruvec->lru_lock);
+ if (lruvec) {
+ spin_unlock_irq(&lruvec->lru_lock);
+ lruvec = NULL;
+ }
putback_lru_page(page);
- spin_lock_irq(&lruvec->lru_lock);
continue;
}

@@ -1876,12 +1876,7 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
* list_add(&page->lru,)
* list_add(&page->lru,) //corrupt
*/
- new_lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
- if (new_lruvec != lruvec) {
- if (lruvec)
- spin_unlock_irq(&lruvec->lru_lock);
- lruvec = lock_page_lruvec_irq(page);
- }
+ lruvec = relock_page_lruvec_irq(page, lruvec);
SetPageLRU(page);

if (unlikely(put_page_testzero(page))) {
@@ -1890,8 +1885,8 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,

if (unlikely(PageCompound(page))) {
spin_unlock_irq(&lruvec->lru_lock);
+ lruvec = NULL;
destroy_compound_page(page);
- spin_lock_irq(&lruvec->lru_lock);
} else
list_add(&page->lru, &pages_to_free);

--
1.8.3.1