mm: page_alloc: do not cache reclaim distances

pgdat->reclaim_nodes tracks if a remote node is allowed to be reclaimed
by zone_reclaim due to its distance.  As it is expected that
zone_reclaim_mode will be rarely enabled it is unreasonable for all
machines to take a penalty.  Fortunately, the zone_reclaim_mode() path
is already slow and it is the path that takes the hit.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index fac5509..c1dbe0b 100644 (file)
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -763,7 +763,6 @@ typedef struct pglist_data {
        unsigned long node_spanned_pages; /* total size of physical page
                                             range, including holes */
        int node_id;
-       nodemask_t reclaim_nodes;       /* Nodes allowed to reclaim from */
        wait_queue_head_t kswapd_wait;
        wait_queue_head_t pfmemalloc_wait;
        struct task_struct *kswapd;     /* Protected by lock_memory_hotplug() */

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index dfe954f..9f13bcf 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1850,16 +1850,8 @@ static bool zone_local(struct zone *local_zone, struct zone *zone)
 
 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
 {
-       return node_isset(local_zone->node, zone->zone_pgdat->reclaim_nodes);
-}
-
-static void __paginginit init_zone_allows_reclaim(int nid)
-{
-       int i;
-
-       for_each_node_state(i, N_MEMORY)
-               if (node_distance(nid, i) <= RECLAIM_DISTANCE)
-                       node_set(i, NODE_DATA(nid)->reclaim_nodes);
+       return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) <
+                               RECLAIM_DISTANCE;
 }
 
 #else  /* CONFIG_NUMA */
@@ -1893,9 +1885,6 @@ static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
        return true;
 }
 
-static inline void init_zone_allows_reclaim(int nid)
-{
-}
 #endif /* CONFIG_NUMA */
 
 /*
@@ -4933,8 +4922,6 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
 
        pgdat->node_id = nid;
        pgdat->node_start_pfn = node_start_pfn;
-       if (node_state(nid, N_MEMORY))
-               init_zone_allows_reclaim(nid);
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
        get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
 #endif