path: root/mm
diff options
authorGerald Schaefer <gerald.schaefer@de.ibm.com>2008-04-28 02:13:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 08:58:25 -0700
commit8fe627ec5b7c47b1654dff50536d9709863295a3 (patch)
tree78511553eb4111224e89ef02a9436d0db382694b /mm
parent6d779079bfd1196e077bb1d0a906c37ae770b102 (diff)
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 <schwidefsky@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
1 files changed, 1 insertions, 0 deletions
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 */