[PATCH v9 16/20] mm/swap: only change the lru_lock iff page's lruvec is different

Alex Shi
2020-03-02T11:00:26Z

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

Signed-off-by: Alex Shi <alex.shi-KPsoFbNs7GizrGE5bRqYAgC/G2K4zDHf@public.gmane.org>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
Cc: Konstantin Khlebnikov <khlebnikov-XoJtRXgx1JseBXzfvpsJ4g@public.gmane.org>
Cc: Hugh Dickins <hughd-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org
---
mm/swap.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/mm/swap.c b/mm/swap.c
index 50c856246f84..74e03589adde 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -197,13 +197,15 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
if (isolation && !TestClearPageLRU(page))
continue;

- 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 (isolation)
SetPageLRU(page);
}
+ if (lruvec)
+ unlock_page_lruvec_irqrestore(lruvec, flags);
+
release_pages(pvec->pages, pvec->nr);
pagevec_reinit(pvec);
}
@@ -821,14 +823,11 @@ void release_pages(struct page **pages, int nr)
}

if (TestClearPageLRU(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);
- }

del_page_from_lru_list(page, lruvec, page_off_lru(page));
}
--
1.8.3.1