From 6237bcd94851e9cf0ecd2520d744779df0f5a9a6 Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hugh@veritas.com>
Date: Sat, 29 Oct 2005 18:15:54 -0700
Subject: [PATCH] [PATCH] mm: zap_pte_range dont dirty anon

zap_pte_range already avoids wasting time to mark_page_accessed on anon pages:
it can also skip anon set_page_dirty - the page only needs to be marked dirty
if shared with another mm, but that will say pte_dirty too.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 mm/memory.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 222c13e46130..fd5d4c6dc762 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -574,12 +574,14 @@ static void zap_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
 						addr) != page->index)
 				set_pte_at(tlb->mm, addr, pte,
 					   pgoff_to_pte(page->index));
-			if (pte_dirty(ptent))
-				set_page_dirty(page);
 			if (PageAnon(page))
 				dec_mm_counter(tlb->mm, anon_rss);
-			else if (pte_young(ptent))
-				mark_page_accessed(page);
+			else {
+				if (pte_dirty(ptent))
+					set_page_dirty(page);
+				if (pte_young(ptent))
+					mark_page_accessed(page);
+			}
 			tlb->freed++;
 			page_remove_rmap(page);
 			tlb_remove_page(tlb, page);
-- 
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