From a3351e525e4768c29aa5d22ef59b5b38e0361e53 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 1 Feb 2006 03:05:39 -0800 Subject: [PATCH] Direct Migration V9: remove_from_swap() to remove swap ptes Add remove_from_swap remove_from_swap() allows the restoration of the pte entries that existed before page migration occurred for anonymous pages by walking the reverse maps. This reduces swap use and establishes regular pte's without the need for page faults. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/rmap.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'mm/rmap.c') diff --git a/mm/rmap.c b/mm/rmap.c index 13fad5fcdf7..f4b91d7aa5c 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -206,6 +206,35 @@ out: return anon_vma; } +#ifdef CONFIG_MIGRATION +/* + * Remove an anonymous page from swap replacing the swap pte's + * through real pte's pointing to valid pages and then releasing + * the page from the swap cache. + * + * Must hold page lock on page. + */ +void remove_from_swap(struct page *page) +{ + struct anon_vma *anon_vma; + struct vm_area_struct *vma; + + if (!PageAnon(page) || !PageSwapCache(page)) + return; + + anon_vma = page_lock_anon_vma(page); + if (!anon_vma) + return; + + list_for_each_entry(vma, &anon_vma->head, anon_vma_node) + remove_vma_swap(vma, page); + + spin_unlock(&anon_vma->lock); + + delete_from_swap_cache(page); +} +#endif + /* * At what user virtual address is page expected in vma? */ -- cgit v1.2.3