Commit 9a14d6ce authored by Jens Axboe's avatar Jens Axboe
Browse files

block: remove debugfs blk_mq_ctx dispatched/merged/completed attributes 



These were added as part of early days debugging for blk-mq, and they
are not really useful anymore. Rather than spend cycles updating them,
just get rid of them.

As a bonus, this shrinks the per-cpu software queue size from 256b
to 192b. That's a whole cacheline less.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 12845906

block/blk-mq-debugfs.c

+0 −54
Original line number Diff line number Diff line
@@ -663,57 +663,6 @@ CTX_RQ_SEQ_OPS(default, HCTX_TYPE_DEFAULT); 
CTX_RQ_SEQ_OPS(read, HCTX_TYPE_READ);

CTX_RQ_SEQ_OPS(poll, HCTX_TYPE_POLL);



static int ctx_dispatched_show(void *data, struct seq_file *m)

{

	struct blk_mq_ctx *ctx = data;



	seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]);

	return 0;

}



static ssize_t ctx_dispatched_write(void *data, const char __user *buf,

				    size_t count, loff_t *ppos)

{

	struct blk_mq_ctx *ctx = data;



	ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0;

	return count;

}



static int ctx_merged_show(void *data, struct seq_file *m)

{

	struct blk_mq_ctx *ctx = data;



	seq_printf(m, "%lu\n", ctx->rq_merged);

	return 0;

}



static ssize_t ctx_merged_write(void *data, const char __user *buf,

				size_t count, loff_t *ppos)

{

	struct blk_mq_ctx *ctx = data;



	ctx->rq_merged = 0;

	return count;

}



static int ctx_completed_show(void *data, struct seq_file *m)

{

	struct blk_mq_ctx *ctx = data;



	seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]);

	return 0;

}



static ssize_t ctx_completed_write(void *data, const char __user *buf,

				   size_t count, loff_t *ppos)

{

	struct blk_mq_ctx *ctx = data;



	ctx->rq_completed[0] = ctx->rq_completed[1] = 0;

	return count;

}



static int blk_mq_debugfs_show(struct seq_file *m, void *v)

{

	const struct blk_mq_debugfs_attr *attr = m->private;
@@ -803,9 +752,6 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { 
	{"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops},

	{"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops},

	{"poll_rq_list", 0400, .seq_ops = &ctx_poll_rq_list_seq_ops},

	{"dispatched", 0600, ctx_dispatched_show, ctx_dispatched_write},

	{"merged", 0600, ctx_merged_show, ctx_merged_write},

	{"completed", 0600, ctx_completed_show, ctx_completed_write},

	{},

};

block/blk-mq-sched.c

+1 −4
Original line number Diff line number Diff line
@@ -387,13 +387,10 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio, 
	 * potentially merge with. Currently includes a hand-wavy stop

	 * count of 8, to not spend too much time checking for merges.

	 */

	if (blk_bio_list_merge(q, &ctx->rq_lists[type], bio, nr_segs)) {

		ctx->rq_merged++;

	if (blk_bio_list_merge(q, &ctx->rq_lists[type], bio, nr_segs))

		ret = true;

	}



	spin_unlock(&ctx->lock);



	return ret;

}

block/blk-mq.c

+0 −3
Original line number Diff line number Diff line
@@ -359,7 +359,6 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, 
	rq->end_io = NULL;

	rq->end_io_data = NULL;



	data->ctx->rq_dispatched[op_is_sync(data->cmd_flags)]++;

	blk_crypto_rq_set_defaults(rq);

	INIT_LIST_HEAD(&rq->queuelist);

	/* tag was already set */
@@ -595,7 +594,6 @@ static void __blk_mq_free_request(struct request *rq) 
void blk_mq_free_request(struct request *rq)

{

	struct request_queue *q = rq->q;

	struct blk_mq_ctx *ctx = rq->mq_ctx;

	struct blk_mq_hw_ctx *hctx = rq->mq_hctx;



	if (rq->rq_flags & (RQF_ELVPRIV | RQF_ELV)) {
@@ -609,7 +607,6 @@ void blk_mq_free_request(struct request *rq) 
		}

	}



	ctx->rq_completed[rq_is_sync(rq)]++;

	if (rq->rq_flags & RQF_MQ_INFLIGHT)

		__blk_mq_dec_active_requests(hctx);

block/blk-mq.h

+0 −7
Original line number Diff line number Diff line
@@ -25,13 +25,6 @@ struct blk_mq_ctx { 
	unsigned short		index_hw[HCTX_MAX_TYPES];

	struct blk_mq_hw_ctx 	*hctxs[HCTX_MAX_TYPES];



	/* incremented at dispatch time */

	unsigned long		rq_dispatched[2];

	unsigned long		rq_merged;



	/* incremented at completion time */

	unsigned long		____cacheline_aligned_in_smp rq_completed[2];



	struct request_queue	*queue;

	struct blk_mq_ctxs      *ctxs;

	struct kobject		kobj;