[PATCH v10 13/15] mm/vmscan: use relock for move_pages_to_lru

From: Alex Shi
Date: Mon Apr 27 2020 - 03:04:00 EST


From: Hugh Dickins <hughd@xxxxxxxxxx>

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

Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: cgroups@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
---
mm/vmscan.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6dd3e1be5bbb..52d8a35fdf6a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1836,15 +1836,15 @@ 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;
}

@@ -1858,12 +1858,7 @@ 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))) {
@@ -1872,8 +1867,8 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,

if (unlikely(PageCompound(page))) {
spin_unlock_irq(&lruvec->lru_lock);
+ lruvec = NULL;
(*get_compound_page_dtor(page))(page);
- spin_lock_irq(&lruvec->lru_lock);
} else
list_add(&page->lru, &pages_to_free);
continue;
@@ -1891,7 +1886,6 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
spin_lock_irq(&orig_lruvec->lru_lock);
}

-
/*
* To save our caller's stack, now use input list for pages to free.
*/
--
1.8.3.1