Messages in this thread Patch in this message | | | From | Andrea Arcangeli <> | Subject | [PATCH 1/4] powerpc: remove superfluous PageTail checks on the pte gup_fast | Date | Sun, 16 Oct 2011 22:40:36 +0200 |
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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 <aarcange@redhat.com>
diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c index b9e1c7f..d7efdbf 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)++; -- 1.7.3.4
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