Commit 5a80bd07 authored by Hengqi Chen's avatar Hengqi Chen Committed by Jens Axboe
Browse files

block: introduce block_io_start/block_io_done tracepoints 

Currently, several BCC ([0]) tools (biosnoop/biostacks/biotop) use
kprobes to blk_account_io_start/blk_account_io_done to implement
their functionalities. This is fragile because the target kernel
functions may be renamed ([1]) or inlined ([2]). So introduce two
new tracepoints for such use cases.

  [0]: https://github.com/iovisor/bcc
  [1]: https://github.com/iovisor/bcc/issues/3954
  [2]: https://github.com/iovisor/bcc/issues/4261



Tested-by: default avatarFrancis Laniel <flaniel@linux.microsoft.com>
Signed-off-by: default avatarHengqi Chen <hengqi.chen@gmail.com>
Tested-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230520084057.1467003-1-hengqi.chen@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a13bd91b

block/blk-mq.c

+4 −0
Original line number Diff line number Diff line
@@ -962,6 +962,8 @@ EXPORT_SYMBOL_GPL(blk_update_request); 


static inline void blk_account_io_done(struct request *req, u64 now)

{

	trace_block_io_done(req);



	/*

	 * Account IO completion.  flush_rq isn't accounted as a

	 * normal IO on queueing nor completion.  Accounting the
@@ -981,6 +983,8 @@ static inline void blk_account_io_done(struct request *req, u64 now) 


static inline void blk_account_io_start(struct request *req)

{

	trace_block_io_start(req);



	if (blk_do_io_stat(req)) {

		/*

		 * All non-passthrough requests are created from a bio with one

include/trace/events/block.h

+26 −0
Original line number Diff line number Diff line
@@ -245,6 +245,32 @@ DEFINE_EVENT(block_rq, block_rq_merge, 
	TP_ARGS(rq)

);



/**

 * block_io_start - insert a request for execution

 * @rq: block IO operation request

 *

 * Called when block operation request @rq is queued for execution

 */

DEFINE_EVENT(block_rq, block_io_start,



	TP_PROTO(struct request *rq),



	TP_ARGS(rq)

);



/**

 * block_io_done - block IO operation request completed

 * @rq: block IO operation request

 *

 * Called when block operation request @rq is completed

 */

DEFINE_EVENT(block_rq, block_io_done,



	TP_PROTO(struct request *rq),



	TP_ARGS(rq)

);



/**

 * block_bio_complete - completed all work on the block operation

 * @q: queue holding the block operation