hugetlb: call mmu notifiers on hugepage cow

When a copy-on-write occurs, we take one of two paths in handle_mm_fault:
through handle_pte_fault for normal pages, or through hugetlb_fault for
huge pages.

In the normal page case, we eventually get to do_wp_page and call mmu
notifiers via ptep_clear_flush_notify.  There is no callout to the mmmu
notifiers in the huge page case.  This patch fixes that.

Signed-off-by: Doug Doan <dougd@cray.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Doug Doan 2010-08-09 17:18:30 -07:00 committed by Linus Torvalds
parent a1b200e27c
commit 3edd4fc953
1 changed files with 6 additions and 0 deletions

View File

@ -2349,11 +2349,17 @@ retry_avoidcopy:
ptep = huge_pte_offset(mm, address & huge_page_mask(h));
if (likely(pte_same(huge_ptep_get(ptep), pte))) {
/* Break COW */
mmu_notifier_invalidate_range_start(mm,
address & huge_page_mask(h),
(address & huge_page_mask(h)) + huge_page_size(h));
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 */
new_page = old_page;
mmu_notifier_invalidate_range_end(mm,
address & huge_page_mask(h),
(address & huge_page_mask(h)) + huge_page_size(h));
}
page_cache_release(new_page);
page_cache_release(old_page);