From caca7cb748571a5b39943a9b3e7081feef055e5e Mon Sep 17 00:00:00 2001
From: Wu Fengguang <fengguang.wu@intel.com>
Date: Tue, 16 Jun 2009 15:31:21 -0700
Subject: [PATCH] readahead: remove one unnecessary radix tree lookup

(hit_readahead_marker != 0) means the page at @offset is present, so we
can search for non-present page starting from @offset+1.

Reported-by: Xu Chenfeng <xcf@ustc.edu.cn>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/readahead.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/readahead.c b/mm/readahead.c
index bd0f0e88b0a1..56731158309b 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -395,7 +395,7 @@ ondemand_readahead(struct address_space *mapping,
 		pgoff_t start;
 
 		rcu_read_lock();
-		start = radix_tree_next_hole(&mapping->page_tree, offset,max+1);
+		start = radix_tree_next_hole(&mapping->page_tree, offset+1,max);
 		rcu_read_unlock();
 
 		if (!start || start - offset > max)
-- 
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