Re: [dm-devel] [PATCH 1/5] block: remove the unused block_sleeprq tracepoint

Damien Le Moal
2020-12-03T08:47:58Z

On 2020/12/01 3:03, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Even if it is just repeating the patch title, a commit message would be nice.
You could also mention when the last use of this tracepoint was removed.

> ---
> include/trace/events/block.h | 18 ------------------
> kernel/trace/blktrace.c | 22 ----------------------
> 2 files changed, 40 deletions(-)
>
> diff --git a/include/trace/events/block.h b/include/trace/events/block.h
> index 34d64ca306b1c7..76459cf750e14d 100644
> --- a/include/trace/events/block.h
> +++ b/include/trace/events/block.h
> @@ -441,24 +441,6 @@ DEFINE_EVENT(block_get_rq, block_getrq,
> TP_ARGS(q, bio, rw)
> );
>
> -/**
> - * block_sleeprq - waiting to get a free request entry in queue for block IO operation
> - * @q: queue for operation
> - * @bio: pending block IO operation (can be %NULL)
> - * @rw: low bit indicates a read (%0) or a write (%1)
> - *
> - * In the case where a request struct cannot be provided for queue @q
> - * the process needs to wait for an request struct to become
> - * available. This tracepoint event is generated each time the
> - * process goes to sleep waiting for request struct become available.
> - */
> -DEFINE_EVENT(block_get_rq, block_sleeprq,
> -
> - TP_PROTO(struct request_queue *q, struct bio *bio, int rw),
> -
> - TP_ARGS(q, bio, rw)
> -);
> -
> /**
> * block_plug - keep operations requests in request queue
> * @q: request queue to plug
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index a482a37848bff7..ced589df304b57 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -959,25 +959,6 @@ static void blk_add_trace_getrq(void *ignore,
> }
> }
>
> -
> -static void blk_add_trace_sleeprq(void *ignore,
> - struct request_queue *q,
> - struct bio *bio, int rw)
> -{
> - if (bio)
> - blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ, 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_SLEEPRQ,
> - 0, 0, NULL, 0);
> - rcu_read_unlock();
> - }
> -}
> -
> static void blk_add_trace_plug(void *ignore, struct request_queue *q)
> {
> struct blk_trace *bt;
> @@ -1164,8 +1145,6 @@ static void blk_register_tracepoints(void)
> WARN_ON(ret);
> ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
> WARN_ON(ret);
> - ret = register_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
> - WARN_ON(ret);
> ret = register_trace_block_plug(blk_add_trace_plug, NULL);
> WARN_ON(ret);
> ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
> @@ -1185,7 +1164,6 @@ static void blk_unregister_tracepoints(void)
> unregister_trace_block_split(blk_add_trace_split, NULL);
> unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
> unregister_trace_block_plug(blk_add_trace_plug, NULL);
> - unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);
> unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
> unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
> unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, NULL);
>

Otherwise, looks good to me.

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

--
Damien Le Moal
Western Digital Research