Re: [dm-devel] [PATCH 5/5] block: remove the request_queue to argument request based tracepoints

Damien Le Moal
2020-12-03T09:07:19Z

On 2020/12/01 3:11, Christoph Hellwig wrote:
> The request_queue can trivially be derived from the request.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> block/blk-merge.c | 2 +-
> block/blk-mq-sched.c | 2 +-
> block/blk-mq.c | 8 +++----
> drivers/md/dm-rq.c | 2 +-
> drivers/s390/scsi/zfcp_fsf.c | 3 +--
> include/linux/blktrace_api.h | 5 ++--
> include/trace/events/block.h | 30 ++++++++++--------------
> kernel/trace/blktrace.c | 44 ++++++++++++++----------------------
> 8 files changed, 39 insertions(+), 57 deletions(-)
>
> diff --git a/block/blk-merge.c b/block/blk-merge.c
> index 4071daa88a5eaf..7497d86fff3834 100644
> --- a/block/blk-merge.c
> +++ b/block/blk-merge.c
> @@ -799,7 +799,7 @@ static struct request *attempt_merge(struct request_queue *q,
> */
> blk_account_io_merge_request(next);
>
> - trace_block_rq_merge(q, next);
> + trace_block_rq_merge(next);
>
> /*
> * ownership of bio passed from next to req, return 'next' for
> diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
> index d1eafe2c045caa..deff4e826e234d 100644
> --- a/block/blk-mq-sched.c
> +++ b/block/blk-mq-sched.c
> @@ -386,7 +386,7 @@ EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge);
>
> void blk_mq_sched_request_inserted(struct request *rq)
> {
> - trace_block_rq_insert(rq->q, rq);
> + trace_block_rq_insert(rq);
> }
> EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted);
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 13636458f32f1c..bb669b415a387e 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -732,7 +732,7 @@ void blk_mq_start_request(struct request *rq)
> {
> struct request_queue *q = rq->q;
>
> - trace_block_rq_issue(q, rq);
> + trace_block_rq_issue(rq);
>
> if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) {
> rq->io_start_time_ns = ktime_get_ns();
> @@ -759,7 +759,7 @@ static void __blk_mq_requeue_request(struct request *rq)
>
> blk_mq_put_driver_tag(rq);
>
> - trace_block_rq_requeue(q, rq);
> + trace_block_rq_requeue(rq);
> rq_qos_requeue(q, rq);
>
> if (blk_mq_request_started(rq)) {
> @@ -1820,7 +1820,7 @@ static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
>
> lockdep_assert_held(&ctx->lock);
>
> - trace_block_rq_insert(hctx->queue, rq);
> + trace_block_rq_insert(rq);
>
> if (at_head)
> list_add(&rq->queuelist, &ctx->rq_lists[type]);
> @@ -1877,7 +1877,7 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
> */
> list_for_each_entry(rq, list, queuelist) {
> BUG_ON(rq->mq_ctx != ctx);
> - trace_block_rq_insert(hctx->queue, rq);
> + trace_block_rq_insert(rq);
> }
>
> spin_lock(&ctx->lock);
> diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
> index 729a72ec30ccae..13b4385f4d5a92 100644
> --- a/drivers/md/dm-rq.c
> +++ b/drivers/md/dm-rq.c
> @@ -397,7 +397,7 @@ static int map_request(struct dm_rq_target_io *tio)
> }
>
> /* The target has remapped the I/O so dispatch it */
> - trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
> + trace_block_rq_remap(clone, disk_devt(dm_disk(md)),
> blk_rq_pos(rq));
> ret = dm_dispatch_clone_request(clone, rq);
> if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) {
> diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
> index 6cb963a0677714..37d450f4695281 100644
> --- a/drivers/s390/scsi/zfcp_fsf.c
> +++ b/drivers/s390/scsi/zfcp_fsf.c
> @@ -2359,8 +2359,7 @@ static void zfcp_fsf_req_trace(struct zfcp_fsf_req *req, struct scsi_cmnd *scsi)
> }
> }
>
> - blk_add_driver_data(scsi->request->q, scsi->request, &blktrc,
> - sizeof(blktrc));
> + blk_add_driver_data(scsi->request, &blktrc, sizeof(blktrc));
> }
>
> /**
> diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
> index 3b6ff5902edce6..05556573b896a2 100644
> --- a/include/linux/blktrace_api.h
> +++ b/include/linux/blktrace_api.h
> @@ -75,8 +75,7 @@ static inline bool blk_trace_note_message_enabled(struct request_queue *q)
> return ret;
> }
>
> -extern void blk_add_driver_data(struct request_queue *q, struct request *rq,
> - void *data, size_t len);
> +extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
> extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
> struct block_device *bdev,
> char __user *arg);
> @@ -90,7 +89,7 @@ extern struct attribute_group blk_trace_attr_group;
> #else /* !CONFIG_BLK_DEV_IO_TRACE */
> # define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
> # define blk_trace_shutdown(q) do { } while (0)
> -# define blk_add_driver_data(q, rq, data, len) do {} while (0)
> +# define blk_add_driver_data(rq, data, len) do {} while (0)
> # define blk_trace_setup(q, name, dev, bdev, arg) (-ENOTTY)
> # define blk_trace_startstop(q, start) (-ENOTTY)
> # define blk_trace_remove(q) (-ENOTTY)
> diff --git a/include/trace/events/block.h b/include/trace/events/block.h
> index 8fb89574d8677f..0d782663a005dc 100644
> --- a/include/trace/events/block.h
> +++ b/include/trace/events/block.h
> @@ -64,7 +64,6 @@ DEFINE_EVENT(block_buffer, block_dirty_buffer,
>
> /**
> * block_rq_requeue - place block IO request back on a queue
> - * @q: queue holding operation
> * @rq: block IO operation request
> *
> * The block operation request @rq is being placed back into queue
> @@ -73,9 +72,9 @@ DEFINE_EVENT(block_buffer, block_dirty_buffer,
> */
> TRACE_EVENT(block_rq_requeue,
>
> - TP_PROTO(struct request_queue *q, struct request *rq),
> + TP_PROTO(struct request *rq),
>
> - TP_ARGS(q, rq),
> + TP_ARGS(rq),
>
> TP_STRUCT__entry(
> __field( dev_t, dev )
> @@ -147,9 +146,9 @@ TRACE_EVENT(block_rq_complete,
>
> DECLARE_EVENT_CLASS(block_rq,
>
> - TP_PROTO(struct request_queue *q, struct request *rq),
> + TP_PROTO(struct request *rq),
>
> - TP_ARGS(q, rq),
> + TP_ARGS(rq),
>
> TP_STRUCT__entry(
> __field( dev_t, dev )
> @@ -181,7 +180,6 @@ DECLARE_EVENT_CLASS(block_rq,
>
> /**
> * block_rq_insert - insert block operation request into queue
> - * @q: target queue
> * @rq: block IO operation request
> *
> * Called immediately before block operation request @rq is inserted
> @@ -191,14 +189,13 @@ DECLARE_EVENT_CLASS(block_rq,
> */
> DEFINE_EVENT(block_rq, block_rq_insert,
>
> - TP_PROTO(struct request_queue *q, struct request *rq),
> + TP_PROTO(struct request *rq),
>
> - TP_ARGS(q, rq)
> + TP_ARGS(rq)
> );
>
> /**
> * block_rq_issue - issue pending block IO request operation to device driver
> - * @q: queue holding operation
> * @rq: block IO operation operation request
> *
> * Called when block operation request @rq from queue @q is sent to a
> @@ -206,14 +203,13 @@ DEFINE_EVENT(block_rq, block_rq_insert,
> */
> DEFINE_EVENT(block_rq, block_rq_issue,
>
> - TP_PROTO(struct request_queue *q, struct request *rq),
> + TP_PROTO(struct request *rq),
>
> - TP_ARGS(q, rq)
> + TP_ARGS(rq)
> );
>
> /**
> * block_rq_merge - merge request with another one in the elevator
> - * @q: queue holding operation
> * @rq: block IO operation operation request
> *
> * Called when block operation request @rq from queue @q is merged to another
> @@ -221,9 +217,9 @@ DEFINE_EVENT(block_rq, block_rq_issue,
> */
> DEFINE_EVENT(block_rq, block_rq_merge,
>
> - TP_PROTO(struct request_queue *q, struct request *rq),
> + TP_PROTO(struct request *rq),
>
> - TP_ARGS(q, rq)
> + TP_ARGS(rq)
> );
>
> /**
> @@ -491,7 +487,6 @@ TRACE_EVENT(block_bio_remap,
>
> /**
> * block_rq_remap - map request for a block operation request
> - * @q: queue holding the operation
> * @rq: block IO operation request
> * @dev: device for the operation
> * @from: original sector for the operation
> @@ -502,10 +497,9 @@ TRACE_EVENT(block_bio_remap,
> */
> TRACE_EVENT(block_rq_remap,
>
> - TP_PROTO(struct request_queue *q, struct request *rq, dev_t dev,
> - sector_t from),
> + TP_PROTO(struct request *rq, dev_t dev, sector_t from),
>
> - TP_ARGS(q, rq, dev, from),
> + TP_ARGS(rq, dev, from),
>
> TP_STRUCT__entry(
> __field( dev_t, dev )
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index 405637144a0389..7839a78205c243 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -795,12 +795,12 @@ static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
> #endif
>
> static u64
> -blk_trace_request_get_cgid(struct request_queue *q, struct request *rq)
> +blk_trace_request_get_cgid(struct request *rq)
> {
> if (!rq->bio)
> return 0;
> /* Use the first bio */
> - return blk_trace_bio_get_cgid(q, rq->bio);
> + return blk_trace_bio_get_cgid(rq->q, rq->bio);
> }
>
> /*
> @@ -841,40 +841,35 @@ static void blk_add_trace_rq(struct request *rq, int error,
> rcu_read_unlock();
> }
>
> -static void blk_add_trace_rq_insert(void *ignore,
> - struct request_queue *q, struct request *rq)
> +static void blk_add_trace_rq_insert(void *ignore, struct request *rq)
> {
> blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT,
> - blk_trace_request_get_cgid(q, rq));
> + blk_trace_request_get_cgid(rq));
> }
>
> -static void blk_add_trace_rq_issue(void *ignore,
> - struct request_queue *q, struct request *rq)
> +static void blk_add_trace_rq_issue(void *ignore, struct request *rq)
> {
> blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE,
> - blk_trace_request_get_cgid(q, rq));
> + blk_trace_request_get_cgid(rq));
> }
>
> -static void blk_add_trace_rq_merge(void *ignore,
> - struct request_queue *q, struct request *rq)
> +static void blk_add_trace_rq_merge(void *ignore, struct request *rq)
> {
> blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_BACKMERGE,
> - blk_trace_request_get_cgid(q, rq));
> + blk_trace_request_get_cgid(rq));
> }
>
> -static void blk_add_trace_rq_requeue(void *ignore,
> - struct request_queue *q,
> - struct request *rq)
> +static void blk_add_trace_rq_requeue(void *ignore, struct request *rq)
> {
> blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE,
> - blk_trace_request_get_cgid(q, rq));
> + blk_trace_request_get_cgid(rq));
> }
>
> static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
> int error, unsigned int nr_bytes)
> {
> blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE,
> - blk_trace_request_get_cgid(rq->q, rq));
> + blk_trace_request_get_cgid(rq));
> }
>
> /**
> @@ -1037,16 +1032,14 @@ static void blk_add_trace_bio_remap(void *ignore, struct bio *bio, dev_t dev,
> * Add a trace for that action.
> *
> **/
> -static void blk_add_trace_rq_remap(void *ignore,
> - struct request_queue *q,
> - struct request *rq, dev_t dev,
> +static void blk_add_trace_rq_remap(void *ignore, struct request *rq, dev_t dev,
> sector_t from)
> {
> struct blk_trace *bt;
> struct blk_io_trace_remap r;
>
> rcu_read_lock();
> - bt = rcu_dereference(q->blk_trace);
> + bt = rcu_dereference(rq->q->blk_trace);
> if (likely(!bt)) {
> rcu_read_unlock();
> return;
> @@ -1058,13 +1051,12 @@ static void blk_add_trace_rq_remap(void *ignore,
>
> __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
> rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
> - sizeof(r), &r, blk_trace_request_get_cgid(q, rq));
> + sizeof(r), &r, blk_trace_request_get_cgid(rq));
> rcu_read_unlock();
> }
>
> /**
> * blk_add_driver_data - Add binary message with driver-specific data
> - * @q: queue the io is for
> * @rq: io request
> * @data: driver-specific data
> * @len: length of driver-specific data
> @@ -1073,14 +1065,12 @@ static void blk_add_trace_rq_remap(void *ignore,
> * Some drivers might want to write driver-specific data per request.
> *
> **/
> -void blk_add_driver_data(struct request_queue *q,
> - struct request *rq,
> - void *data, size_t len)
> +void blk_add_driver_data(struct request *rq, void *data, size_t len)
> {
> struct blk_trace *bt;
>
> rcu_read_lock();
> - bt = rcu_dereference(q->blk_trace);
> + bt = rcu_dereference(rq->q->blk_trace);
> if (likely(!bt)) {
> rcu_read_unlock();
> return;
> @@ -1088,7 +1078,7 @@ void blk_add_driver_data(struct request_queue *q,
>
> __blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
> BLK_TA_DRV_DATA, 0, len, data,
> - blk_trace_request_get_cgid(q, rq));
> + blk_trace_request_get_cgid(rq));
> rcu_read_unlock();
> }
> EXPORT_SYMBOL_GPL(blk_add_driver_data);
>

Looks good to me.

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

--
Damien Le Moal
Western Digital Research