tracing/events: convert block trace points to TRACE_EVENT()
TRACE_EVENT is a more generic way to define tracepoints. Doing so adds
these new capabilities to this tracepoint:
- zero-copy and per-cpu splice() tracing
- binary tracing without printf overhead
- structured logging records exposed under /debug/tracing/events
- trace events embedded in function tracer output and other plugins
- user-defined, per tracepoint filter expressions
...
Cons:
- no dev_t info for the output of plug, unplug_timer and unplug_io events.
no dev_t info for getrq and sleeprq events if bio == NULL.
no dev_t info for rq_abort,...,rq_requeue events if rq->rq_disk == NULL.
This is mainly because we can't get the deivce from a request queue.
But this may change in the future.
- A packet command is converted to a string in TP_assign, not TP_print.
While blktrace do the convertion just before output.
Since pc requests should be rather rare, this is not a big issue.
- In blktrace, an event can have 2 different print formats, but a TRACE_EVENT
has a unique format, which means we have some unused data in a trace entry.
The overhead is minimized by using __dynamic_array() instead of __array().
I've benchmarked the ioctl blktrace vs the splice based TRACE_EVENT tracing:
dd dd + ioctl blktrace dd + TRACE_EVENT (splice)
1 7.36s, 42.7 MB/s 7.50s, 42.0 MB/s 7.41s, 42.5 MB/s
2 7.43s, 42.3 MB/s 7.48s, 42.1 MB/s 7.43s, 42.4 MB/s
3 7.38s, 42.6 MB/s 7.45s, 42.2 MB/s 7.41s, 42.5 MB/s
So the overhead of tracing is very small, and no regression when using
those trace events vs blktrace.
And the binary output of TRACE_EVENT is much smaller than blktrace:
# ls -l -h
-rw-r--r-- 1 root root 8.8M 06-09 13:24 sda.blktrace.0
-rw-r--r-- 1 root root 195K 06-09 13:24 sda.blktrace.1
-rw-r--r-- 1 root root 2.7M 06-09 13:25 trace_splice.out
Following are some comparisons between TRACE_EVENT and blktrace:
plug:
kjournald-480 [000] 303.084981: block_plug: [kjournald]
kjournald-480 [000] 303.084981: 8,0 P N [kjournald]
unplug_io:
kblockd/0-118 [000] 300.052973: block_unplug_io: [kblockd/0] 1
kblockd/0-118 [000] 300.052974: 8,0 U N [kblockd/0] 1
remap:
kjournald-480 [000] 303.085042: block_remap: 8,0 W 102736992 + 8 <- (8,8) 33384
kjournald-480 [000] 303.085043: 8,0 A W 102736992 + 8 <- (8,8) 33384
bio_backmerge:
kjournald-480 [000] 303.085086: block_bio_backmerge: 8,0 W 102737032 + 8 [kjournald]
kjournald-480 [000] 303.085086: 8,0 M W 102737032 + 8 [kjournald]
getrq:
kjournald-480 [000] 303.084974: block_getrq: 8,0 W 102736984 + 8 [kjournald]
kjournald-480 [000] 303.084975: 8,0 G W 102736984 + 8 [kjournald]
bash-2066 [001] 1072.953770: 8,0 G N [bash]
bash-2066 [001] 1072.953773: block_getrq: 0,0 N 0 + 0 [bash]
rq_complete:
konsole-2065 [001] 300.053184: block_rq_complete: 8,0 W () 103669040 + 16 [0]
konsole-2065 [001] 300.053191: 8,0 C W 103669040 + 16 [0]
ksoftirqd/1-7 [001] 1072.953811: 8,0 C N (5a 00 08 00 00 00 00 00 24 00) [0]
ksoftirqd/1-7 [001] 1072.953813: block_rq_complete: 0,0 N (5a 00 08 00 00 00 00 00 24 00) 0 + 0 [0]
rq_insert:
kjournald-480 [000] 303.084985: block_rq_insert: 8,0 W 0 () 102736984 + 8 [kjournald]
kjournald-480 [000] 303.084986: 8,0 I W 102736984 + 8 [kjournald]
Changelog from v2 -> v3:
- use the newly introduced __dynamic_array().
Changelog from v1 -> v2:
- use __string() instead of __array() to minimize the memory required
to store hex dump of rq->cmd().
- support large pc requests.
- add missing blk_fill_rwbs_rq() in block_rq_requeue TRACE_EVENT.
- some cleanups.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A2DF669.5070905@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
new file mode 100644
index 0000000..a99d1e5
--- /dev/null
+++ b/include/trace/events/block.h
@@ -0,0 +1,483 @@
+#if !defined(_TRACE_BLOCK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_BLOCK_H
+
+#include <linux/blktrace_api.h>
+#include <linux/blkdev.h>
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM block
+
+TRACE_EVENT(block_rq_abort,
+
+ TP_PROTO(struct request_queue *q, struct request *rq),
+
+ TP_ARGS(q, rq),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __field( int, errors )
+ __array( char, rwbs, 6 )
+ __dynamic_array( char, cmd, blk_cmd_buf_len(rq) )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
+ __entry->sector = blk_pc_request(rq) ? 0 : rq->hard_sector;
+ __entry->nr_sector = blk_pc_request(rq) ?
+ 0 : rq->hard_nr_sectors;
+ __entry->errors = rq->errors;
+
+ blk_fill_rwbs_rq(__entry->rwbs, rq);
+ blk_dump_cmd(__get_str(cmd), rq);
+ ),
+
+ TP_printk("%d,%d %s (%s) %llu + %u [%d]",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->rwbs, __get_str(cmd),
+ __entry->sector, __entry->nr_sector, __entry->errors)
+);
+
+TRACE_EVENT(block_rq_insert,
+
+ TP_PROTO(struct request_queue *q, struct request *rq),
+
+ TP_ARGS(q, rq),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __field( unsigned int, bytes )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ __dynamic_array( char, cmd, blk_cmd_buf_len(rq) )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
+ __entry->sector = blk_pc_request(rq) ? 0 : rq->hard_sector;
+ __entry->nr_sector = blk_pc_request(rq) ?
+ 0 : rq->hard_nr_sectors;
+ __entry->bytes = blk_pc_request(rq) ? rq->data_len : 0;
+
+ blk_fill_rwbs_rq(__entry->rwbs, rq);
+ blk_dump_cmd(__get_str(cmd), rq);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %u (%s) %llu + %u [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->rwbs, __entry->bytes, __get_str(cmd),
+ __entry->sector, __entry->nr_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_rq_issue,
+
+ TP_PROTO(struct request_queue *q, struct request *rq),
+
+ TP_ARGS(q, rq),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __field( unsigned int, bytes )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ __dynamic_array( char, cmd, blk_cmd_buf_len(rq) )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
+ __entry->sector = blk_pc_request(rq) ? 0 : rq->hard_sector;
+ __entry->nr_sector = blk_pc_request(rq) ?
+ 0 : rq->hard_nr_sectors;
+ __entry->bytes = blk_pc_request(rq) ? rq->data_len : 0;
+
+ blk_fill_rwbs_rq(__entry->rwbs, rq);
+ blk_dump_cmd(__get_str(cmd), rq);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %u (%s) %llu + %u [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->rwbs, __entry->bytes, __get_str(cmd),
+ __entry->sector, __entry->nr_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_rq_requeue,
+
+ TP_PROTO(struct request_queue *q, struct request *rq),
+
+ TP_ARGS(q, rq),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __field( int, errors )
+ __array( char, rwbs, 6 )
+ __dynamic_array( char, cmd, blk_cmd_buf_len(rq) )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
+ __entry->sector = blk_pc_request(rq) ? 0 : rq->hard_sector;
+ __entry->nr_sector = blk_pc_request(rq) ?
+ 0 : rq->hard_nr_sectors;
+ __entry->errors = rq->errors;
+
+ blk_fill_rwbs_rq(__entry->rwbs, rq);
+ blk_dump_cmd(__get_str(cmd), rq);
+ ),
+
+ TP_printk("%d,%d %s (%s) %llu + %u [%d]",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->rwbs, __get_str(cmd),
+ __entry->sector, __entry->nr_sector, __entry->errors)
+);
+
+TRACE_EVENT(block_rq_complete,
+
+ TP_PROTO(struct request_queue *q, struct request *rq),
+
+ TP_ARGS(q, rq),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __field( int, errors )
+ __array( char, rwbs, 6 )
+ __dynamic_array( char, cmd, blk_cmd_buf_len(rq) )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
+ __entry->sector = blk_pc_request(rq) ? 0 : rq->hard_sector;
+ __entry->nr_sector = blk_pc_request(rq) ?
+ 0 : rq->hard_nr_sectors;
+ __entry->errors = rq->errors;
+
+ blk_fill_rwbs_rq(__entry->rwbs, rq);
+ blk_dump_cmd(__get_str(cmd), rq);
+ ),
+
+ TP_printk("%d,%d %s (%s) %llu + %u [%d]",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->rwbs, __get_str(cmd),
+ __entry->sector, __entry->nr_sector, __entry->errors)
+);
+TRACE_EVENT(block_bio_bounce,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio),
+
+ TP_ARGS(q, bio),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio->bi_bdev->bd_dev;
+ __entry->sector = bio->bi_sector;
+ __entry->nr_sector = bio->bi_size >> 9;
+ blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %llu + %u [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->nr_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_bio_complete,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio),
+
+ TP_ARGS(q, bio),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned, nr_sector )
+ __field( int, error )
+ __array( char, rwbs, 6 )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio->bi_bdev->bd_dev;
+ __entry->sector = bio->bi_sector;
+ __entry->nr_sector = bio->bi_size >> 9;
+ blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+ ),
+
+ TP_printk("%d,%d %s %llu + %u [%d]",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->nr_sector, __entry->error)
+);
+
+TRACE_EVENT(block_bio_backmerge,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio),
+
+ TP_ARGS(q, bio),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio->bi_bdev->bd_dev;
+ __entry->sector = bio->bi_sector;
+ __entry->nr_sector = bio->bi_size >> 9;
+ blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %llu + %u [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->nr_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_bio_frontmerge,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio),
+
+ TP_ARGS(q, bio),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned, nr_sector )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio->bi_bdev->bd_dev;
+ __entry->sector = bio->bi_sector;
+ __entry->nr_sector = bio->bi_size >> 9;
+ blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %llu + %u [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->nr_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_bio_queue,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio),
+
+ TP_ARGS(q, bio),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio->bi_bdev->bd_dev;
+ __entry->sector = bio->bi_sector;
+ __entry->nr_sector = bio->bi_size >> 9;
+ blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %llu + %u [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->nr_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_getrq,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio, int rw),
+
+ TP_ARGS(q, bio, rw),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio ? bio->bi_bdev->bd_dev : 0;
+ __entry->sector = bio ? bio->bi_sector : 0;
+ __entry->nr_sector = bio ? bio->bi_size >> 9 : 0;
+ blk_fill_rwbs(__entry->rwbs,
+ bio ? bio->bi_rw : 0, __entry->nr_sector);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %llu + %u [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->nr_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_sleeprq,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio, int rw),
+
+ TP_ARGS(q, bio, rw),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio ? bio->bi_bdev->bd_dev : 0;
+ __entry->sector = bio ? bio->bi_sector : 0;
+ __entry->nr_sector = bio ? bio->bi_size >> 9 : 0;
+ blk_fill_rwbs(__entry->rwbs,
+ bio ? bio->bi_rw : 0, __entry->nr_sector);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %llu + %u [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->nr_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_plug,
+
+ TP_PROTO(struct request_queue *q),
+
+ TP_ARGS(q),
+
+ TP_STRUCT__entry(
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("[%s]", __entry->comm)
+);
+
+TRACE_EVENT(block_unplug_timer,
+
+ TP_PROTO(struct request_queue *q),
+
+ TP_ARGS(q),
+
+ TP_STRUCT__entry(
+ __field( int, nr_rq )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->nr_rq = q->rq.count[READ] + q->rq.count[WRITE];
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("[%s] %d", __entry->comm, __entry->nr_rq)
+);
+
+TRACE_EVENT(block_unplug_io,
+
+ TP_PROTO(struct request_queue *q),
+
+ TP_ARGS(q),
+
+ TP_STRUCT__entry(
+ __field( int, nr_rq )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->nr_rq = q->rq.count[READ] + q->rq.count[WRITE];
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("[%s] %d", __entry->comm, __entry->nr_rq)
+);
+
+TRACE_EVENT(block_split,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio,
+ unsigned int new_sector),
+
+ TP_ARGS(q, bio, new_sector),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( sector_t, new_sector )
+ __array( char, rwbs, 6 )
+ __array( char, comm, TASK_COMM_LEN )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio->bi_bdev->bd_dev;
+ __entry->sector = bio->bi_sector;
+ __entry->new_sector = new_sector;
+ blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+ memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+ ),
+
+ TP_printk("%d,%d %s %llu / %llu [%s]",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->new_sector, __entry->comm)
+);
+
+TRACE_EVENT(block_remap,
+
+ TP_PROTO(struct request_queue *q, struct bio *bio, dev_t dev,
+ sector_t from),
+
+ TP_ARGS(q, bio, dev, from),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __field( dev_t, old_dev )
+ __field( sector_t, old_sector )
+ __array( char, rwbs, 6 )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = bio->bi_bdev->bd_dev;
+ __entry->sector = bio->bi_sector;
+ __entry->nr_sector = bio->bi_size >> 9;
+ __entry->old_dev = dev;
+ __entry->old_sector = from;
+ blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+ ),
+
+ TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",
+ MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
+ __entry->sector, __entry->nr_sector,
+ MAJOR(__entry->old_dev), MINOR(__entry->old_dev),
+ __entry->old_sector)
+);
+
+#endif /* _TRACE_BLOCK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
+