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authorChristoph Lameter <clameter@sgi.com>2006-02-01 12:05:39 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-01 17:53:16 +0100
commita3351e525e4768c29aa5d22ef59b5b38e0361e53 (patch)
tree457ab54f402b471c5158e8b361d059e88ab8cd62 /mm/rmap.c
parent[PATCH] Direct Migration V9: migrate_pages() extension (diff)
downloadlinux-a3351e525e4768c29aa5d22ef59b5b38e0361e53.tar.xz
linux-a3351e525e4768c29aa5d22ef59b5b38e0361e53.zip
[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 <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 13fad5fcdf79..f4b91d7aa5cf 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?
*/