[PATCH] Set CCISS driver VM read-ahead to 1024K

From: Torben Mathiasen <torben.mathiasen@hp.com>

After a lot of testing and measuring we decided to increase the read-ahead
for the CISS driver in 2.6 to 1MB.

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index d4f508644b1f28d5d23c69a03b742660182b618c..4c3ace285a5af67672f81b84f1607ad9b6b8f433 100644 (file)
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -103,7 +103,7 @@ static struct board_type products[] = {
 /*define how many times we will try a command because of bus resets */
 #define MAX_CMD_RETRIES 3
 
-#define READ_AHEAD      128
+#define READ_AHEAD      256
 #define NR_CMDS                 384 /* #commands that can be outstanding */
 #define MAX_CTLR 8
 
@@ -2501,6 +2501,7 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
        if (!q)
                goto clean4;
 
+       q->backing_dev_info.ra_pages = READ_AHEAD;
        hba[i]->queue = q;
        q->queuedata = hba[i];