diff -urpN linux-2.6.23.8-clean/mm/backing-dev.c linux-2.6.23.8-patched/mm/backing-dev.c
--- linux-2.6.23.8-clean/mm/backing-dev.c	2007-10-12 11:43:44.000000000 -0500
+++ linux-2.6.23.8-patched/mm/backing-dev.c	2007-11-21 11:39:59.000000000 -0600
@@ -48,6 +48,10 @@ long congestion_wait(int rw, long timeou
 	DEFINE_WAIT(wait);
 	wait_queue_head_t *wqh = &congestion_wqh[rw];
 
+	if ((current->flags & PF_LESS_THROTTLE) && printk_ratelimit()) {
+		printk(KERN_WARNING "PF_LESS_THROTTLE process %s[%i] entered congestion_wait!\n", current->comm, current->pid);
+		dump_stack();
+	}
 	prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
 	ret = io_schedule_timeout(timeout);
 	finish_wait(wqh, &wait);