diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 23ecd0a892df..28bcdc433d88 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -716,6 +716,30 @@ int page_mkclean(struct page *page) EXPORT_SYMBOL_GPL(page_mkclean); /** + * page_move_anon_rmap - move a page to our anon_vma + * @page: the page to move to our anon_vma + * @vma: the vma the page belongs to + * @address: the user virtual address mapped + * + * When a page belongs exclusively to one process after a COW event, + * that page can be moved into the anon_vma that belongs to just that + * process, so the rmap code will not search the parent or sibling + * processes. + */ +void page_move_anon_rmap(struct page *page, + struct vm_area_struct *vma, unsigned long address) +{ + struct anon_vma *anon_vma = vma->anon_vma; + + VM_BUG_ON(!PageLocked(page)); + VM_BUG_ON(!anon_vma); + VM_BUG_ON(page->index != linear_page_index(vma, address)); + + anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON; + page->mapping = (struct address_space *) anon_vma; +} + +/** * __page_set_anon_rmap - setup new anonymous rmap * @page: the page to add the mapping to * @vma: the vm area in which the mapping is added |