mm: remove zone_lru_lock() function, access ->lru_lock directly

We have common pattern to access lru_lock from a page pointer:
	zone_lru_lock(page_zone(page))

Which is silly, because it unfolds to this:
	&NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)]->zone_pgdat->lru_lock
while we can simply do
	&NODE_DATA(page_to_nid(page))->lru_lock

Remove zone_lru_lock() function, since it's only complicate things.  Use
'page_pgdat(page)->lru_lock' pattern instead.

[aryabinin@virtuozzo.com: a slightly better version of __split_huge_page()]
  Link: http://lkml.kernel.org/r/20190301121651.7741-1-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/20190228083329.31892-2-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/mm/page_idle.c b/mm/page_idle.c
index b9e4b42b33ab..0b39ec0c945c 100644
--- a/mm/page_idle.c
+++ b/mm/page_idle.c
@@ -31,7 +31,7 @@
 static struct page *page_idle_get_page(unsigned long pfn)
 {
         struct page *page;
-        struct zone *zone;
+        pg_data_t *pgdat;
 
         if (!pfn_valid(pfn))
                 return NULL;
@@ -41,13 +41,13 @@ static struct page *page_idle_get_page(unsigned long pfn)
             !get_page_unless_zero(page))
                 return NULL;
 
-        zone = page_zone(page);
-        spin_lock_irq(zone_lru_lock(zone));
+        pgdat = page_pgdat(page);
+        spin_lock_irq(&pgdat->lru_lock);
         if (unlikely(!PageLRU(page))) {
                 put_page(page);
                 page = NULL;
         }
-        spin_unlock_irq(zone_lru_lock(zone));
+        spin_unlock_irq(&pgdat->lru_lock);
         return page;
 }