mm: add & use zone_end_pfn() and zone_spans_pfn()

Add 2 helpers (zone_end_pfn() and zone_spans_pfn()) to reduce code
duplication.

This also switches to using them in compaction (where an additional
variable needed to be renamed), page_alloc, vmstat, memory_hotplug, and
kmemleak.

Note that in compaction.c I avoid calling zone_end_pfn() repeatedly
because I expect at some point the sycronization issues with start_pfn &
spanned_pages will need fixing, either by actually using the seqlock or
clever memory barrier usage.

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Hansen <dave@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 752a705c77c2..83dd5fbf5e60 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1300,9 +1300,8 @@ static void kmemleak_scan(void)
          */
         lock_memory_hotplug();
         for_each_online_node(i) {
-                pg_data_t *pgdat = NODE_DATA(i);
-                unsigned long start_pfn = pgdat->node_start_pfn;
-                unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
+                unsigned long start_pfn = node_start_pfn(i);
+                unsigned long end_pfn = node_end_pfn(i);
                 unsigned long pfn;
 
                 for (pfn = start_pfn; pfn < end_pfn; pfn++) {