mm, vmscan: move lru_lock to the node

Node-based reclaim requires node-based LRUs and locking.  This is a
preparation patch that just moves the lru_lock to the node so later
patches are easier to review.  It is a mechanical change but note this
patch makes contention worse because the LRU lock is hotter and direct
reclaim and kswapd can contend on the same lock even when reclaiming
from different zones.

Link: http://lkml.kernel.org/r/1467970510-21195-3-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7d4ff81b973f..5760c626c309 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5904,6 +5904,7 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
         init_waitqueue_head(&pgdat->kcompactd_wait);
 #endif
         pgdat_page_ext_init(pgdat);
+        spin_lock_init(&pgdat->lru_lock);
 
         for (j = 0; j < MAX_NR_ZONES; j++) {
                 struct zone *zone = pgdat->node_zones + j;
@@ -5958,10 +5959,9 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
                 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
 #endif
                 zone->name = zone_names[j];
+                zone->zone_pgdat = pgdat;
                 spin_lock_init(&zone->lock);
-                spin_lock_init(&zone->lru_lock);
                 zone_seqlock_init(zone);
-                zone->zone_pgdat = pgdat;
                 zone_pcp_init(zone);
 
                 /* For bootup, initialized properly in watermark setup */