mm: kill one if loop in __free_pages_bootmem()

We should not check loop+1 with loop end in loop body.  Just duplicate two
lines code to avoid it.

That will help a bit when we have huge amount of pages on system with
16TiB memory.

Signed-off-by: Yinghai Lu <[email protected]>
Cc: Mel Gorman <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 7 insertions, 7 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2748fc6a9003..8c68ef13cefa 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -751,19 +751,19 @@ static void __free_pages_ok(struct page *page, unsigned int order)
 void __init __free_pages_bootmem(struct page *page, unsigned int order)
 {
 	unsigned int nr_pages = 1 << order;
+	struct page *p = page;
 	unsigned int loop;
 
-	prefetchw(page);
-	for (loop = 0; loop < nr_pages; loop++) {
-		struct page *p = &page[loop];
-
-		if (loop + 1 < nr_pages)
-			prefetchw(p + 1);
+	prefetchw(p);
+	for (loop = 0; loop < (nr_pages - 1); loop++, p++) {
+		prefetchw(p + 1);
 		__ClearPageReserved(p);
 		set_page_count(p, 0);
 	}
+	__ClearPageReserved(p);
+	set_page_count(p, 0);
 
-	page_zone(page)->managed_pages += 1 << order;
+	page_zone(page)->managed_pages += nr_pages;
 	set_page_refcounted(page);
 	__free_pages(page, order);
 }