[NACK until know reason for this and checked it's safe on all arches.]

---
 drivers/md/dm-raid1.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6.27/drivers/md/dm-raid1.c
===================================================================
--- linux-2.6.27.orig/drivers/md/dm-raid1.c	2008-10-15 12:52:40.000000000 +0100
+++ linux-2.6.27/drivers/md/dm-raid1.c	2008-10-15 12:52:43.000000000 +0100
@@ -20,8 +20,8 @@
 
 #define MAX_RECOVERY 1	/* Maximum number of regions recovered in parallel. */
 
-#define DM_IO_PAGES 64
-#define DM_KCOPYD_PAGES 64
+#define DM_IO_PAGES 128
+#define DM_KCOPYD_PAGES 256
 
 #define DM_RAID1_HANDLE_ERRORS 0x01
 #define errors_handled(p)	((p)->features & DM_RAID1_HANDLE_ERRORS)