--- linux-2.6.32-131.6.1/fs/buffer.c
+++ linux-2.6.32-131.6.1-pdo/fs/buffer.c
@@ -1250,8 +1250,7 @@
  * The LRUs themselves only need locking against invalidate_bh_lrus.  We use
  * a local interrupt disable for that.
  */
-
-#define BH_LRU_SIZE	8
+#define BH_LRU_SIZE	CONFIG_BH_LRU_SIZE
 
 struct bh_lru {
 	struct buffer_head *bhs[BH_LRU_SIZE];
--- linux-2.6.32-131.6.1/fs/Kconfig
+++ linux-2.6.32-131.6.1-pdo/fs/Kconfig
@@ -253,4 +253,13 @@
 source "fs/nls/Kconfig"
 source "fs/dlm/Kconfig"
 
+config BH_LRU_SIZE
+      int "buffer head per-CPU LRU size"
+      range 8 64
+      default "8"
+      help
+        This sets the per-CPU LRU size for buffer heads in memory.
+        More complex filesystems may be modiyfing multiple blocks
+        within a single transaction, so keeping the buffer heads in
+        CPU-local cache speeds up modifations significantly.
 endmenu