pwd
/usr/src/linux-2.6.37

patch -p0 < patch
patching file linux-2.6/block/cfq-iosched.c
Hunk #1 FAILED at 498.
Hunk #2 FAILED at 2229.
Hunk #3 FAILED at 2499.
Hunk #4 FAILED at 3359.
4 out of 4 hunks FAILED -- saving rejects to file linux-2.6/block/cfq-iosched.c.rej

cat patch
 block/cfq-iosched.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Index: linux-2.6/block/cfq-iosched.c
===================================================================
--- linux-2.6.orig/block/cfq-iosched.c	2011-02-22 13:23:25.000000000 -0500
+++ linux-2.6/block/cfq-iosched.c	2011-02-22 14:01:21.515363676 -0500
@@ -498,7 +498,7 @@ static inline bool cfq_bio_sync(struct b
 static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
 {
 	if (cfqd->busy_queues) {
-		cfq_log(cfqd, "schedule dispatch");
+		cfq_log(cfqd, "schedule dispatch: busy_queues=%d rq_queued=%d rq_in_driver=%d", cfqd->busy_queues, cfqd->rq_queued, cfqd->rq_in_driver);
 		kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work);
 	}
 }
@@ -2229,6 +2229,8 @@ static struct cfq_queue *cfq_select_queu
 {
 	struct cfq_queue *cfqq, *new_cfqq = NULL;

+	cfq_log(cfqd, "select_queue: busy_queues=%d rq_queued=%d rq_in_driver=%d", cfqd->busy_queues, cfqd->rq_queued, cfqd->rq_in_driver);
+
 	cfqq = cfqd->active_queue;
 	if (!cfqq)
 		goto new_queue;
@@ -2499,8 +2501,10 @@ static int cfq_dispatch_requests(struct
 		return cfq_forced_dispatch(cfqd);

 	cfqq = cfq_select_queue(cfqd);
-	if (!cfqq)
+	if (!cfqq) {
+		cfq_log(cfqd, "select: no cfqq selected");
 		return 0;
+	}

 	/*
 	 * Dispatch a request from this cfqq, if it is allowed
@@ -3359,7 +3363,7 @@ static void cfq_insert_request(struct re
 	struct cfq_data *cfqd = q->elevator->elevator_data;
 	struct cfq_queue *cfqq = RQ_CFQQ(rq);

-	cfq_log_cfqq(cfqd, cfqq, "insert_request");
+	cfq_log_cfqq(cfqd, cfqq, "insert_request: busy_queues=%d rq_queued=%d rq_in_driver=%d", cfqd->busy_queues, cfqd->rq_queued, cfqd->rq_in_driver);
 	cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc);

 	rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]);

md5sum block/cfq-iosched.c
cf11d5bb5aec76d79c0eaba47e29d5c0  block/cfq-iosched.c