From 8fe627ec5b7c47b1654dff50536d9709863295a3 Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Mon, 28 Apr 2008 02:13:28 -0700 Subject: hugetlbfs: add missing TLB flush to hugetlb_cow() A cow break on a hugetlbfs page with page_count > 1 will set a new pte with set_huge_pte_at(), w/o any tlb flush operation. The old pte will remain in the tlb and subsequent write access to the page will result in a page fault loop, for as long as it may take until the tlb is flushed from somewhere else. This patch introduces an architecture-specific huge_ptep_clear_flush() function, which is called before the the set_huge_pte_at() in hugetlb_cow(). ATTENTION: This is just a nop on all architectures for now, the s390 implementation will come with our large page patch later. Other architectures should define their own huge_ptep_clear_flush() if needed. Acked-by: Martin Schwidefsky Signed-off-by: Gerald Schaefer Cc: Paul Mundt Cc: "Luck, Tony" Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "David S. Miller" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 1 + 1 file changed, 1 insertion(+) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index d36e1f11a5f..262d0a93d2b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -892,6 +892,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, ptep = huge_pte_offset(mm, address & HPAGE_MASK); if (likely(pte_same(*ptep, pte))) { /* Break COW */ + huge_ptep_clear_flush(vma, address, ptep); set_huge_pte_at(mm, address, ptep, make_huge_pte(vma, new_page, 1)); /* Make the old page be freed below */ -- cgit v1.2.3