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@xxxxxxxxxxxxx> Acked-by: Mike Snitzer <snitzer@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 2fdb4a4..0e6f765 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 60ae7c3..4c2301d 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 */ -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
