mm, pagevec: release/reacquire lru_lock on pgdat change

With node-lru, the locking is based on the pgdat.  Previously it was
required that a pagevec drain released one zone lru_lock and acquired
another zone lru_lock on every zone change.  Now, it's only necessary if
the node changes.  The end-result is fewer lock release/acquires if the
pages are all on the same node but in different zones.

Link: http://lkml.kernel.org/r/1468588165-12461-4-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swap.c b/mm/swap.c
index 77af473635fe0d968334b5946635692a36194117..75c63bb2a1da1dc0c3e55600e9db1618949df87a 100644 (file)
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -179,26 +179,26 @@ static void pagevec_lru_move_fn(struct pagevec *pvec,
        void *arg)
 {
        int i;
-       struct zone *zone = NULL;
+       struct pglist_data *pgdat = NULL;
        struct lruvec *lruvec;
        unsigned long flags = 0;
 
        for (i = 0; i < pagevec_count(pvec); i++) {
                struct page *page = pvec->pages[i];
-               struct zone *pagezone = page_zone(page);
+               struct pglist_data *pagepgdat = page_pgdat(page);
 
-               if (pagezone != zone) {
-                       if (zone)
-                               spin_unlock_irqrestore(zone_lru_lock(zone), flags);
-                       zone = pagezone;
-                       spin_lock_irqsave(zone_lru_lock(zone), flags);
+               if (pagepgdat != pgdat) {
+                       if (pgdat)
+                               spin_unlock_irqrestore(&pgdat->lru_lock, flags);
+                       pgdat = pagepgdat;
+                       spin_lock_irqsave(&pgdat->lru_lock, flags);
                }
 
-               lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+               lruvec = mem_cgroup_page_lruvec(page, pgdat);
                (*move_fn)(page, lruvec, arg);
        }
-       if (zone)
-               spin_unlock_irqrestore(zone_lru_lock(zone), flags);
+       if (pgdat)
+               spin_unlock_irqrestore(&pgdat->lru_lock, flags);
        release_pages(pvec->pages, pvec->nr, pvec->cold);
        pagevec_reinit(pvec);
 }