From e2d0bd2b924d74d5e0d4f395f8f4730d125e198c Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 11 Sep 2013 14:20:37 -0700 Subject: [PATCH] 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 Cc: Mel Gorman Acked-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2748fc6a..8c68ef1 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); } -- 2.7.4