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From: Wu Fengguang <fengguang.wu@intel.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Wu Fengguang <fengguang.wu@intel.com>
Cc: Ying Han <yinghan@google.com>
Subject: [PATCH 3/9] readahead: remove one unnecessary radix tree lookup
Date: Fri, 10 Apr 2009 14:10:00 +0800	[thread overview]
Message-ID: <20090410061254.052551915@intel.com> (raw)
In-Reply-To: 20090410060957.442203404@intel.com

[-- Attachment #1: readahead-interleaved-offset.patch --]
[-- Type: text/plain, Size: 659 bytes --]

(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>
---
 mm/readahead.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- mm.orig/mm/readahead.c
+++ mm/mm/readahead.c
@@ -395,7 +395,7 @@ ondemand_readahead(struct address_space 
 		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)

-- 


  parent reply	other threads:[~2009-04-10  6:18 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-10  6:09 [PATCH 0/9] filemap and readahead fixes for linux-next Wu Fengguang
2009-04-10  6:09 ` [PATCH 1/9] readahead: move max_sane_readahead() calls into force_page_cache_readahead() Wu Fengguang
2009-04-10  6:09 ` [PATCH 2/9] readahead: apply max_sane_readahead() limit in ondemand_readahead() Wu Fengguang
2009-04-10  6:10 ` Wu Fengguang [this message]
2009-04-10  6:10 ` [PATCH 4/9] readahead: increase interleaved readahead size Wu Fengguang
2009-04-10  6:10 ` [PATCH 5/9] readahead: remove sync/async readahead call dependency Wu Fengguang
2009-04-10  6:10 ` [PATCH 6/9] readahead: clean up and simplify the code for filemap page fault readahead Wu Fengguang
2009-04-10 23:48   ` Andrew Morton
2009-04-11 13:58     ` KOSAKI Motohiro
2009-04-11 18:49       ` Andrew Morton
2009-04-12 23:16         ` KOSAKI Motohiro
2009-04-10  6:10 ` [PATCH 7/9] readahead: sequential mmap readahead Wu Fengguang
2009-04-10 23:34   ` Andrew Morton
2009-04-12  6:50     ` Wu Fengguang
2009-04-12  7:09     ` [PATCH] readahead: enforce full sync mmap readahead size Wu Fengguang
2009-04-12 15:15       ` Linus Torvalds
2009-04-13 13:53         ` Wu Fengguang
2009-04-14  7:01         ` Nick Piggin
2009-04-10  6:10 ` [PATCH 8/9] readahead: enforce full readahead size on async mmap readahead Wu Fengguang
2009-04-10  6:10 ` [PATCH 9/9] readahead: record mmap read-around states in file_ra_state Wu Fengguang
2009-04-10 23:38   ` Andrew Morton
2009-04-11  4:24     ` Wu Fengguang

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