Mark new anonymous pages mlocked if they are in a mlocked VMA.

Avoid putting pages onto the LRU that are allocated in a VMA
with VM_LOCKED set. NR_MLOCK will be more accurate.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.20/mm/memory.c
===================================================================
--- linux-2.6.20.orig/mm/memory.c	2007-02-14 12:52:01.000000000 -0800
+++ linux-2.6.20/mm/memory.c	2007-02-14 12:52:36.000000000 -0800
@@ -906,7 +906,16 @@
 				unsigned long address)
 {
 	inc_mm_counter(vma->vm_mm, anon_rss);
-	lru_cache_add_active(page);
+	if (vma->vm_flags & VM_LOCKED) {
+		/*
+		 * Page is new and therefore not on the LRU
+		 * so we can directly mark it as mlocked
+		 */
+		SetPageMlocked(page);
+		ClearPageActive(page);
+		inc_zone_page_state(page, NR_MLOCK);
+	} else
+		lru_cache_add_active(page);
 	page_add_new_anon_rmap(page, vma, address);
 }