[PATCH 09/21] mm/page_alloc: calculate node_spanned_pages from pfns

[Doug Berger <opendmb-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Since the start and end pfns of the node are passed as arguments
to calculate_node_totalpages() they might as well be used to
specify the node_spanned_pages value for the node rather than
accumulating the spans of member zones.

This prevents the need for additional adjustments if zones are
allowed to overlap.

Signed-off-by: Doug Berger <opendmb-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 mm/page_alloc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6bf76bbc0308..b6074961fb59 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7452,7 +7452,7 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
 						unsigned long node_start_pfn,
 						unsigned long node_end_pfn)
 {
-	unsigned long realtotalpages = 0, totalpages = 0;
+	unsigned long realtotalpages = 0;
 	enum zone_type i;
 
 	for (i = 0; i < MAX_NR_ZONES; i++) {
@@ -7483,11 +7483,10 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
 		zone->present_early_pages = real_size;
 #endif
 
-		totalpages += size;
 		realtotalpages += real_size;
 	}
 
-	pgdat->node_spanned_pages = totalpages;
+	pgdat->node_spanned_pages = node_end_pfn - node_start_pfn;
 	pgdat->node_present_pages = realtotalpages;
 	pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
 }
-- 
2.25.1