commit 2868ef7b39490e6b41c2c61cd9a5cd891e778b54
author Vivek Goyal <vgoyal@redhat.com> Thu Dec 03 12:59:48 2009 -0500
committer Jens Axboe <jens.axboe@oracle.com> Thu Dec 03 19:28:52 2009 +0100
tree e50e169e984d8bd201de2f73f98e31a65c028feb
parent b1c3576961847da26c91b1e97f226bb66be5fa3f

blkio: Some debugging aids for CFQ

o Some debugging aids for CFQ.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

block/cfq-iosched.c

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 8bc31a5..662d4e55 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -341,8 +341,21 @@
 CFQ_CFQQ_FNS(deep);
 #undef CFQ_CFQQ_FNS
 
+#ifdef CONFIG_DEBUG_CFQ_IOSCHED
+#define cfq_log_cfqq(cfqd, cfqq, fmt, args...)	\
+	blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \
+			cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
+			blkg_path(&(cfqq)->cfqg->blkg), ##args);
+
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)				\
+	blk_add_trace_msg((cfqd)->queue, "%s " fmt,			\
+				blkg_path(&(cfqg)->blkg), ##args);      \
+
+#else
 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...)	\
 	blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args)
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)		do {} while (0);
+#endif
 #define cfq_log(cfqd, fmt, args...)	\
 	blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)
 
@@ -832,6 +845,7 @@
 	if (cfqg->nr_cfqq)
 		return;
 
+	cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
 	cfqg->on_st = false;
 	cfqd->nr_groups--;
 	st->total_weight -= cfqg->weight;
@@ -889,6 +903,9 @@
 		cfqg->saved_serving_prio = cfqd->serving_prio;
 	} else
 		cfqg->saved_workload_slice = 0;
+
+	cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
+					st->min_vdisktime);
 }
 
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
@@ -3102,7 +3119,7 @@
 	unsigned long now;
 
 	now = jiffies;
-	cfq_log_cfqq(cfqd, cfqq, "complete");
+	cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", !!rq_noidle(rq));
 
 	cfq_update_hw_tag(cfqd);