[PATCH v7 06/10] mm/swap: only change the lru_lock iff page's lruvec is different

Alex Shi
2019-12-25T09:05:04Z

Since we introduced relock_page_lruvec, we could use it in more place
to reduce spin_locks.

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-kernel@vger.kernel.org
Cc: cgroups@vger.kernel.org
Cc: linux-mm@kvack.org
---
mm/swap.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c
index 97e108be4f92..84a845968e1d 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -196,11 +196,12 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
for (i = 0; i < pagevec_count(pvec); i++) {
struct page *page = pvec->pages[i];

- lruvec = lock_page_lruvec_irqsave(page, &flags);
+ lruvec = relock_page_lruvec_irqsave(page, lruvec, &flags);

(*move_fn)(page, lruvec, arg);
- unlock_page_lruvec_irqrestore(lruvec, flags);
}
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec, flags);

release_pages(pvec->pages, pvec->nr);
pagevec_reinit(pvec);
@@ -819,14 +820,11 @@ void release_pages(struct page **pages, int nr)
}

if (PageLRU(page)) {
- struct lruvec *new_lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
+ struct lruvec *pre_lruvec = lruvec;

- if (new_lruvec != lruvec) {
- if (lruvec)
- unlock_page_lruvec_irqrestore(lruvec, flags);
+ lruvec = relock_page_lruvec_irqsave(page, lruvec, &flags);
+ if (pre_lruvec != lruvec)
lock_batch = 0;
- lruvec = lock_page_lruvec_irqsave(page, &flags);
- }

VM_BUG_ON_PAGE(!PageLRU(page), page);
__ClearPageLRU(page);
--
1.8.3.1