From 5db7016cf280d1505807b013aca0cd4a3f0882a7 Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Wed, 2 Nov 2011 13:37:03 -0700 Subject: [PATCH] powerpc: remove superfluous PageTail checks on the pte gup_fast commit 2839bdc1bfc0af76a2f0f11eca011590520a04fa upstream. This part of gup_fast doesn't seem capable of handling hugetlbfs ptes, those should be handled by gup_hugepd only, so these checks are superfluous. Plus if this wasn't a noop, it would have oopsed because, the insistence of using the speculative refcounting would trigger a VM_BUG_ON if a tail page was encountered in the page_cache_get_speculative(). Signed-off-by: Andrea Arcangeli Cc: Peter Zijlstra Cc: Hugh Dickins Cc: Johannes Weiner Cc: Rik van Riel Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Benjamin Herrenschmidt Acked-by: David Gibson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/mm/gup.c | 13 ------------- 1 file changed, 13 deletions(-) diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c index b9e1c7ff5f6d..d7efdbf640c7 100644 --- a/arch/powerpc/mm/gup.c +++ b/arch/powerpc/mm/gup.c @@ -16,17 +16,6 @@ #ifdef __HAVE_ARCH_PTE_SPECIAL -static inline void get_huge_page_tail(struct page *page) -{ - /* - * __split_huge_page_refcount() cannot run - * from under us. - */ - VM_BUG_ON(page_mapcount(page) < 0); - VM_BUG_ON(atomic_read(&page->_count) != 0); - atomic_inc(&page->_mapcount); -} - /* * The performance critical leaf functions are made noinline otherwise gcc * inlines everything into a single function which results in too much @@ -58,8 +47,6 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, put_page(page); return 0; } - if (PageTail(page)) - get_huge_page_tail(page); pages[*nr] = page; (*nr)++; -- 2.39.5