summary refs log tree commit diff
path: root/include
diff options
context:
space:
mode:
authorJun'ichi Nomura <j-nomura@ce.jp.nec.com>2013-09-21 13:57:47 -0600
committerJens Axboe <axboe@kernel.dk>2013-09-21 13:57:47 -0600
commit75afb352991ff1cd3cf5955bfe611de6d83a0c87 (patch)
tree2873c9fa5c098c4dd5134f395207af9463cc21d9 /include
parent7652113c2f508b1c8176640dcd034730fe79bc48 (diff)
downloadlinux-75afb352991ff1cd3cf5955bfe611de6d83a0c87.tar.gz
block: Add nr_bios to block_rq_remap tracepoint
Adding the number of bios in a remapped request to 'block_rq_remap'
tracepoint.

Request remapper clones bios in a request to track the completion
status of each bio. So the number of bios can be useful information
for investigation.

Related discussions:
  http://www.redhat.com/archives/dm-devel/2013-August/msg00084.html
  http://www.redhat.com/archives/dm-devel/2013-September/msg00024.html

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
-rw-r--r--include/linux/blkdev.h11
-rw-r--r--include/trace/events/block.h6
2 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 2fdb4a451b49..0e6f765aa1f5 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -862,6 +862,17 @@ static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
 	return blk_queue_get_max_sectors(q, rq->cmd_flags);
 }
 
+static inline unsigned int blk_rq_count_bios(struct request *rq)
+{
+	unsigned int nr_bios = 0;
+	struct bio *bio;
+
+	__rq_for_each_bio(bio, rq)
+		nr_bios++;
+
+	return nr_bios;
+}
+
 /*
  * Request issue related functions.
  */
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 60ae7c3db912..4c2301d2ef1a 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -618,6 +618,7 @@ TRACE_EVENT(block_rq_remap,
 		__field( unsigned int,	nr_sector	)
 		__field( dev_t,		old_dev		)
 		__field( sector_t,	old_sector	)
+		__field( unsigned int,	nr_bios		)
 		__array( char,		rwbs,	RWBS_LEN)
 	),
 
@@ -627,15 +628,16 @@ TRACE_EVENT(block_rq_remap,
 		__entry->nr_sector	= blk_rq_sectors(rq);
 		__entry->old_dev	= dev;
 		__entry->old_sector	= from;
+		__entry->nr_bios	= blk_rq_count_bios(rq);
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
 	),
 
-	TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",
+	TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu %u",
 		  MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
 		  (unsigned long long)__entry->sector,
 		  __entry->nr_sector,
 		  MAJOR(__entry->old_dev), MINOR(__entry->old_dev),
-		  (unsigned long long)__entry->old_sector)
+		  (unsigned long long)__entry->old_sector, __entry->nr_bios)
 );
 
 #endif /* _TRACE_BLOCK_H */