Re: [dm-devel] [PATCH 2/5] block: simplify and extended the block_bio_merge tracepoint class

Damien Le Moal
2020-12-03T08:57:39Z

In the patch title:

s/extended/extend

On 2020/12/01 3:06, Christoph Hellwig wrote:
> The block_bio_merge tracepoint class can be reused for most bio-based
> tracepoints. For that is just needs to lose the superflous and rq

s/is/it
s/superflous/superfluous

> parameters.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> block/blk-core.c | 2 +-
> block/blk-merge.c | 4 +-
> block/blk-mq.c | 2 +-
> block/bounce.c | 2 +-
> include/trace/events/block.h | 158 ++++++++---------------------------
> kernel/trace/blktrace.c | 41 +++------
> 6 files changed, 48 insertions(+), 161 deletions(-)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index cee568389b7e11..cb24654983e1e4 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -907,7 +907,7 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio)
> blkcg_bio_issue_init(bio);
>
> if (!bio_flagged(bio, BIO_TRACE_COMPLETION)) {
> - trace_block_bio_queue(q, bio);
> + trace_block_bio_queue(bio);
> /* Now that enqueuing has been traced, we need to trace
> * completion as well.
> */
> diff --git a/block/blk-merge.c b/block/blk-merge.c
> index cb351ab9b77dbd..1a46d5bbd399e3 100644
> --- a/block/blk-merge.c
> +++ b/block/blk-merge.c
> @@ -922,7 +922,7 @@ static enum bio_merge_status bio_attempt_back_merge(struct request *req,
> if (!ll_back_merge_fn(req, bio, nr_segs))
> return BIO_MERGE_FAILED;
>
> - trace_block_bio_backmerge(req->q, req, bio);
> + trace_block_bio_backmerge(bio);
> rq_qos_merge(req->q, req, bio);
>
> if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
> @@ -946,7 +946,7 @@ static enum bio_merge_status bio_attempt_front_merge(struct request *req,
> if (!ll_front_merge_fn(req, bio, nr_segs))
> return BIO_MERGE_FAILED;
>
> - trace_block_bio_frontmerge(req->q, req, bio);
> + trace_block_bio_frontmerge(bio);
> rq_qos_merge(req->q, req, bio);
>
> if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index a2593748fa5342..13636458f32f1c 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2183,7 +2183,7 @@ blk_qc_t blk_mq_submit_bio(struct bio *bio)
> goto queue_exit;
> }
>
> - trace_block_getrq(q, bio, bio->bi_opf);
> + trace_block_getrq(bio);
>
> rq_qos_track(q, rq, bio);
>
> diff --git a/block/bounce.c b/block/bounce.c
> index 162a6eee89996a..d3f51acd6e3b51 100644
> --- a/block/bounce.c
> +++ b/block/bounce.c
> @@ -340,7 +340,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
> }
> }
>
> - trace_block_bio_bounce(q, *bio_orig);
> + trace_block_bio_bounce(*bio_orig);
>
> bio->bi_flags |= (1 << BIO_BOUNCED);
>
> diff --git a/include/trace/events/block.h b/include/trace/events/block.h
> index 76459cf750e14d..506c29dc7c76fd 100644
> --- a/include/trace/events/block.h
> +++ b/include/trace/events/block.h
> @@ -226,45 +226,6 @@ DEFINE_EVENT(block_rq, block_rq_merge,
> TP_ARGS(q, rq)
> );
>
> -/**
> - * block_bio_bounce - used bounce buffer when processing block operation
> - * @q: queue holding the block operation
> - * @bio: block operation
> - *
> - * A bounce buffer was used to handle the block operation @bio in @q.
> - * This occurs when hardware limitations prevent a direct transfer of
> - * data between the @bio data memory area and the IO device. Use of a
> - * bounce buffer requires extra copying of data and decreases
> - * performance.
> - */
> -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, RWBS_LEN )
> - __array( char, comm, TASK_COMM_LEN )
> - ),
> -
> - TP_fast_assign(
> - __entry->dev = bio_dev(bio);
> - __entry->sector = bio->bi_iter.bi_sector;
> - __entry->nr_sector = bio_sectors(bio);
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.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,
> - (unsigned long long)__entry->sector,
> - __entry->nr_sector, __entry->comm)
> -);
> -
> /**
> * block_bio_complete - completed all work on the block operation
> * @q: queue holding the block operation
> @@ -301,11 +262,11 @@ TRACE_EVENT(block_bio_complete,
> __entry->nr_sector, __entry->error)
> );
>
> -DECLARE_EVENT_CLASS(block_bio_merge,
> +DECLARE_EVENT_CLASS(block_bio,
>
> - TP_PROTO(struct request_queue *q, struct request *rq, struct bio *bio),
> + TP_PROTO(struct bio *bio),
>
> - TP_ARGS(q, rq, bio),
> + TP_ARGS(bio),
>
> TP_STRUCT__entry(
> __field( dev_t, dev )
> @@ -329,116 +290,63 @@ DECLARE_EVENT_CLASS(block_bio_merge,
> __entry->nr_sector, __entry->comm)
> );
>
> +/**
> + * block_bio_bounce - used bounce buffer when processing block operation
> + * @bio: block operation
> + *
> + * A bounce buffer was used to handle the block operation @bio in @q.
> + * This occurs when hardware limitations prevent a direct transfer of
> + * data between the @bio data memory area and the IO device. Use of a
> + * bounce buffer requires extra copying of data and decreases
> + * performance.
> + */
> +DEFINE_EVENT(block_bio, block_bio_bounce,
> + TP_PROTO(struct bio *bio),
> + TP_ARGS(bio)
> +);
> +
> /**
> * block_bio_backmerge - merging block operation to the end of an existing operation
> - * @q: queue holding operation
> - * @rq: request bio is being merged into
> * @bio: new block operation to merge
> *
> - * Merging block request @bio to the end of an existing block request
> - * in queue @q.
> + * Merging block request @bio to the end of an existing block request.
> */
> -DEFINE_EVENT(block_bio_merge, block_bio_backmerge,
> -
> - TP_PROTO(struct request_queue *q, struct request *rq, struct bio *bio),
> -
> - TP_ARGS(q, rq, bio)
> +DEFINE_EVENT(block_bio, block_bio_backmerge,
> + TP_PROTO(struct bio *bio),
> + TP_ARGS(bio)
> );
>
> /**
> * block_bio_frontmerge - merging block operation to the beginning of an existing operation
> - * @q: queue holding operation
> - * @rq: request bio is being merged into
> * @bio: new block operation to merge
> *
> - * Merging block IO operation @bio to the beginning of an existing block
> - * operation in queue @q.
> + * Merging block IO operation @bio to the beginning of an existing block request.
> */
> -DEFINE_EVENT(block_bio_merge, block_bio_frontmerge,
> -
> - TP_PROTO(struct request_queue *q, struct request *rq, struct bio *bio),
> -
> - TP_ARGS(q, rq, bio)
> +DEFINE_EVENT(block_bio, block_bio_frontmerge,
> + TP_PROTO(struct bio *bio),
> + TP_ARGS(bio)
> );
>
> /**
> * block_bio_queue - putting new block IO operation in queue
> - * @q: queue holding operation
> * @bio: new block operation
> *
> * About to place the block IO operation @bio into queue @q.
> */
> -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, RWBS_LEN )
> - __array( char, comm, TASK_COMM_LEN )
> - ),
> -
> - TP_fast_assign(
> - __entry->dev = bio_dev(bio);
> - __entry->sector = bio->bi_iter.bi_sector;
> - __entry->nr_sector = bio_sectors(bio);
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.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,
> - (unsigned long long)__entry->sector,
> - __entry->nr_sector, __entry->comm)
> -);
> -
> -DECLARE_EVENT_CLASS(block_get_rq,
> -
> - 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, RWBS_LEN )
> - __array( char, comm, TASK_COMM_LEN )
> - ),
> -
> - TP_fast_assign(
> - __entry->dev = bio ? bio_dev(bio) : 0;
> - __entry->sector = bio ? bio->bi_iter.bi_sector : 0;
> - __entry->nr_sector = bio ? bio_sectors(bio) : 0;
> - blk_fill_rwbs(__entry->rwbs,
> - bio ? bio->bi_opf : 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,
> - (unsigned long long)__entry->sector,
> - __entry->nr_sector, __entry->comm)
> +DEFINE_EVENT(block_bio, block_bio_queue,
> + TP_PROTO(struct bio *bio),
> + TP_ARGS(bio)
> );
>
> /**
> * block_getrq - get a free request entry in queue for block IO operations
> - * @q: queue for operations
> * @bio: pending block IO operation (can be %NULL)
> - * @rw: low bit indicates a read (%0) or a write (%1)
> *
> - * A request struct for queue @q has been allocated to handle the
> - * block IO operation @bio.
> + * A request struct has been allocated to handle the block IO operation @bio.
> */
> -DEFINE_EVENT(block_get_rq, block_getrq,
> -
> - TP_PROTO(struct request_queue *q, struct bio *bio, int rw),
> -
> - TP_ARGS(q, bio, rw)
> +DEFINE_EVENT(block_bio, block_getrq,
> + TP_PROTO(struct bio *bio),
> + TP_ARGS(bio)
> );
>
> /**
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index ced589df304b57..7ab88e00c15765 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -906,10 +906,9 @@ static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
> rcu_read_unlock();
> }
>
> -static void blk_add_trace_bio_bounce(void *ignore,
> - struct request_queue *q, struct bio *bio)
> +static void blk_add_trace_bio_bounce(void *ignore, struct bio *bio)
> {
> - blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0);
> + blk_add_trace_bio(bio->bi_disk->queue, bio, BLK_TA_BOUNCE, 0);
> }
>
> static void blk_add_trace_bio_complete(void *ignore,
> @@ -919,44 +918,24 @@ static void blk_add_trace_bio_complete(void *ignore,
> blk_status_to_errno(bio->bi_status));
> }
>
> -static void blk_add_trace_bio_backmerge(void *ignore,
> - struct request_queue *q,
> - struct request *rq,
> - struct bio *bio)
> +static void blk_add_trace_bio_backmerge(void *ignore, struct bio *bio)
> {
> - blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0);
> + blk_add_trace_bio(bio->bi_disk->queue, bio, BLK_TA_BACKMERGE, 0);
> }
>
> -static void blk_add_trace_bio_frontmerge(void *ignore,
> - struct request_queue *q,
> - struct request *rq,
> - struct bio *bio)
> +static void blk_add_trace_bio_frontmerge(void *ignore, struct bio *bio)
> {
> - blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0);
> + blk_add_trace_bio(bio->bi_disk->queue, bio, BLK_TA_FRONTMERGE, 0);
> }
>
> -static void blk_add_trace_bio_queue(void *ignore,
> - struct request_queue *q, struct bio *bio)
> +static void blk_add_trace_bio_queue(void *ignore, struct bio *bio)
> {
> - blk_add_trace_bio(q, bio, BLK_TA_QUEUE, 0);
> + blk_add_trace_bio(bio->bi_disk->queue, bio, BLK_TA_QUEUE, 0);
> }
>
> -static void blk_add_trace_getrq(void *ignore,
> - struct request_queue *q,
> - struct bio *bio, int rw)
> +static void blk_add_trace_getrq(void *ignore, struct bio *bio)
> {
> - if (bio)
> - blk_add_trace_bio(q, bio, BLK_TA_GETRQ, 0);
> - else {
> - struct blk_trace *bt;
> -
> - rcu_read_lock();
> - bt = rcu_dereference(q->blk_trace);
> - if (bt)
> - __blk_add_trace(bt, 0, 0, rw, 0, BLK_TA_GETRQ, 0, 0,
> - NULL, 0);
> - rcu_read_unlock();
> - }
> + blk_add_trace_bio(bio->bi_disk->queue, bio, BLK_TA_GETRQ, 0);
> }
>
> static void blk_add_trace_plug(void *ignore, struct request_queue *q)
>

With the commit message fixed, looks good to me.

Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>

--
Damien Le Moal
Western Digital Research