mm: convert zone_reclaim to node_reclaim

As reclaim is now per-node based, convert zone_reclaim to be
node_reclaim.  It is possible that a node will be reclaimed multiple
times if it has multiple zones but this is unavoidable without caching
all nodes traversed so far.  The documentation and interface to
userspace is the same from a configuration perspective and will will be
similar in behaviour unless the node-local allocation requests were also
limited to lower zones.

Link: http://lkml.kernel.org/r/1467970510-21195-24-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@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>

3 files changed, 15 insertions, 14 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index e3d6d42722a0..e19c081c794e 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -372,14 +372,6 @@ struct zone {
 	unsigned long		*pageblock_flags;
 #endif /* CONFIG_SPARSEMEM */
 
-#ifdef CONFIG_NUMA
-	/*
-	 * zone reclaim becomes active if more unmapped pages exist.
-	 */
-	unsigned long		min_unmapped_pages;
-	unsigned long		min_slab_pages;
-#endif /* CONFIG_NUMA */
-
 	/* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
 	unsigned long		zone_start_pfn;
 
@@ -525,7 +517,6 @@ struct zone {
 } ____cacheline_internodealigned_in_smp;
 
 enum zone_flags {
-	ZONE_RECLAIM_LOCKED,		/* prevents concurrent reclaim */
 	ZONE_FAIR_DEPLETED,		/* fair zone policy batch depleted */
 };
 
@@ -540,6 +531,7 @@ enum pgdat_flags {
 	PGDAT_WRITEBACK,		/* reclaim scanning has recently found
 					 * many pages under writeback
 					 */
+	PGDAT_RECLAIM_LOCKED,		/* prevents concurrent reclaim */
 };
 
 static inline unsigned long zone_end_pfn(const struct zone *zone)
@@ -688,6 +680,14 @@ typedef struct pglist_data {
 	 */
 	unsigned long		totalreserve_pages;
 
+#ifdef CONFIG_NUMA
+	/*
+	 * zone reclaim becomes active if more unmapped pages exist.
+	 */
+	unsigned long		min_unmapped_pages;
+	unsigned long		min_slab_pages;
+#endif /* CONFIG_NUMA */
+
 	/* Write-intensive fields used by page reclaim */
 	ZONE_PADDING(_pad1_)
 	spinlock_t		lru_lock;
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 2a23ddc96edd..b17cc4830fa6 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -326,13 +326,14 @@ extern int remove_mapping(struct address_space *mapping, struct page *page);
 extern unsigned long vm_total_pages;
 
 #ifdef CONFIG_NUMA
-extern int zone_reclaim_mode;
+extern int node_reclaim_mode;
 extern int sysctl_min_unmapped_ratio;
 extern int sysctl_min_slab_ratio;
-extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
+extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
 #else
-#define zone_reclaim_mode 0
-static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
+#define node_reclaim_mode 0
+static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
+				unsigned int order)
 {
 	return 0;
 }
diff --git a/include/linux/topology.h b/include/linux/topology.h
index afce69296ac0..cb0775e1ee4b 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -54,7 +54,7 @@ int arch_update_cpu_topology(void);
 /*
  * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
  * (in whatever arch specific measurement units returned by node_distance())
- * and zone_reclaim_mode is enabled then the VM will only call zone_reclaim()
+ * and node_reclaim_mode is enabled then the VM will only call node_reclaim()
  * on nodes within this distance.
  */
 #define RECLAIM_DISTANCE 30