From: Nick Piggin <npiggin@suse.de>
Date: Fri, 23 Jun 2006 09:03:22 +0000 (-0700)
Subject: [PATCH] radix-tree: small
X-Git-Tag: v2.6.18-rc1~1081^2~190
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cfd9b7df4abd3257c9e381b0e445817b26a51c0c;p=linux-2.6

[PATCH] radix-tree: small

Reduce radix tree node memory usage by about a factor of 4 for small files
(< 64K).  There are pointer traversal and memory usage costs for large
files with dense pagecache.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 35a2d93b35..7cbdada510 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -33,7 +33,7 @@
 
 
 #ifdef __KERNEL__
-#define RADIX_TREE_MAP_SHIFT	6
+#define RADIX_TREE_MAP_SHIFT	(CONFIG_BASE_SMALL ? 4 : 6)
 #else
 #define RADIX_TREE_MAP_SHIFT	3	/* For more stressful testing */
 #endif