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 <yinghai@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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);
 }