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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 409a825..928a16a 100644 (file)
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -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},
        {},
 };
 

diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index efc1374..e85b755 100644 (file)
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -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;
 }
 

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 633d735..990d214 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -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);
 

diff --git a/block/blk-mq.h b/block/blk-mq.h
index 8be4479..1b91a3f 100644 (file)
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -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;