diff options
| -rw-r--r-- | block/mq-deadline.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/block/mq-deadline.c b/block/mq-deadline.c index aba672a5be1e..04d9d6b3745b 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -51,6 +51,19 @@ enum dd_prio { enum { DD_PRIO_COUNT = 3 }; +/* I/O statistics per I/O priority. */ +struct io_stats_per_prio { + local_t inserted; + local_t merged; + local_t dispatched; + local_t completed; +}; + +/* I/O statistics for all I/O priorities (enum dd_prio). */ +struct io_stats { + struct io_stats_per_prio stats[DD_PRIO_COUNT]; +}; + /* * Deadline scheduler data per I/O priority (enum dd_prio). Requests are * present on both sort_list[] and fifo_list[]. @@ -75,6 +88,8 @@ struct deadline_data { unsigned int batching; /* number of sequential requests made */ unsigned int starved; /* times reads have starved writes */ + struct io_stats __percpu *stats; + /* * settings that change how the i/o scheduler behaves */ @@ -88,6 +103,33 @@ struct deadline_data { spinlock_t zone_lock; }; +/* Count one event of type 'event_type' and with I/O priority 'prio' */ +#define dd_count(dd, event_type, prio) do { \ + struct io_stats *io_stats = get_cpu_ptr((dd)->stats); \ + \ + BUILD_BUG_ON(!__same_type((dd), struct deadline_data *)); \ + BUILD_BUG_ON(!__same_type((prio), enum dd_prio)); \ + local_inc(&io_stats->stats[(prio)].event_type); \ + put_cpu_ptr(io_stats); \ +} while (0) + +/* + * Returns the total number of dd_count(dd, event_type, prio) calls across all + * CPUs. No locking or barriers since it is fine if the returned sum is slightly + * outdated. + */ +#define dd_sum(dd, event_type, prio) ({ \ + unsigned int cpu; \ + u32 sum = 0; \ + \ + BUILD_BUG_ON(!__same_type((dd), struct deadline_data *)); \ + BUILD_BUG_ON(!__same_type((prio), enum dd_prio)); \ + for_each_present_cpu(cpu) \ + sum += local_read(&per_cpu_ptr((dd)->stats, cpu)-> \ + stats[(prio)].event_type); \ + sum; \ +}) + /* Maps an I/O priority class to a deadline scheduler priority. */ static const enum dd_prio ioprio_class_to_prio[] = { [IOPRIO_CLASS_NONE] = DD_BE_PRIO, @@ -187,9 +229,12 @@ static void dd_request_merged(struct request_queue *q, struct request *req, static void dd_merged_requests(struct request_queue *q, struct request *req, struct request *next) { + struct deadline_data *dd = q->elevator->elevator_data; const u8 ioprio_class = dd_rq_ioclass(next); const enum dd_prio prio = ioprio_class_to_prio[ioprio_class]; + dd_count(dd, merged, prio); + /* * if next expires before rq, assign its expire time to rq * and move into next position (next will be deleted) in fifo @@ -225,6 +270,12 @@ deadline_move_request(struct deadline_data *dd, struct dd_per_prio *per_prio, deadline_remove_request(rq->q, per_prio, rq); } +/* Number of requests queued for a given priority level. */ +static u32 dd_queued(struct deadline_data *dd, enum dd_prio prio) +{ + return dd_sum(dd, inserted, prio) - dd_sum(dd, completed, prio); +} + /* * deadline_check_fifo returns 0 if there are no expired requests on the fifo, * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir]) @@ -319,6 +370,8 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd, { struct request *rq, *next_rq; enum dd_data_dir data_dir; + enum dd_prio prio; + u8 ioprio_class; lockdep_assert_held(&dd->lock); @@ -408,6 +461,9 @@ dispatch_request: dd->batching++; deadline_move_request(dd, per_prio, rq); done: + ioprio_class = dd_rq_ioclass(rq); + prio = ioprio_class_to_prio[ioprio_class]; + dd_count(dd, dispatched, prio); /* * If the request needs its target zone locked, do it. */ @@ -491,6 +547,8 @@ static void dd_exit_sched(struct elevator_queue *e) WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_WRITE])); } + free_percpu(dd->stats); + kfree(dd); } @@ -514,6 +572,11 @@ static int dd_init_sched(struct request_queue *q, struct elevator_type *e) eq->elevator_data = dd; + dd->stats = alloc_percpu_gfp(typeof(*dd->stats), + GFP_KERNEL | __GFP_ZERO); + if (!dd->stats) + goto free_dd; + for (prio = 0; prio <= DD_PRIO_MAX; prio++) { struct dd_per_prio *per_prio = &dd->per_prio[prio]; @@ -535,6 +598,9 @@ static int dd_init_sched(struct request_queue *q, struct elevator_type *e) q->elevator = eq; return 0; +free_dd: + kfree(dd); + put_eq: kobject_put(&eq->kobj); return ret; @@ -614,6 +680,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, blk_req_zone_write_unlock(rq); prio = ioprio_class_to_prio[ioprio_class]; + dd_count(dd, inserted, prio); if (blk_mq_sched_try_insert_merge(q, rq)) return; @@ -692,6 +759,8 @@ static void dd_finish_request(struct request *rq) const enum dd_prio prio = ioprio_class_to_prio[ioprio_class]; struct dd_per_prio *per_prio = &dd->per_prio[prio]; + dd_count(dd, completed, prio); + if (blk_queue_is_zoned(q)) { unsigned long flags; @@ -873,6 +942,35 @@ static int dd_async_depth_show(void *data, struct seq_file *m) return 0; } +static int dd_queued_show(void *data, struct seq_file *m) +{ + struct request_queue *q = data; + struct deadline_data *dd = q->elevator->elevator_data; + + seq_printf(m, "%u %u %u\n", dd_queued(dd, DD_RT_PRIO), + dd_queued(dd, DD_BE_PRIO), + dd_queued(dd, DD_IDLE_PRIO)); + return 0; +} + +/* Number of requests owned by the block driver for a given priority. */ +static u32 dd_owned_by_driver(struct deadline_data *dd, enum dd_prio prio) +{ + return dd_sum(dd, dispatched, prio) + dd_sum(dd, merged, prio) + - dd_sum(dd, completed, prio); +} + +static int dd_owned_by_driver_show(void *data, struct seq_file *m) +{ + struct request_queue *q = data; + struct deadline_data *dd = q->elevator->elevator_data; + + seq_printf(m, "%u %u %u\n", dd_owned_by_driver(dd, DD_RT_PRIO), + dd_owned_by_driver(dd, DD_BE_PRIO), + dd_owned_by_driver(dd, DD_IDLE_PRIO)); + return 0; +} + #define DEADLINE_DISPATCH_ATTR(prio) \ static void *deadline_dispatch##prio##_start(struct seq_file *m, \ loff_t *pos) \ @@ -941,6 +1039,8 @@ static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = { {"dispatch0", 0400, .seq_ops = &deadline_dispatch0_seq_ops}, {"dispatch1", 0400, .seq_ops = &deadline_dispatch1_seq_ops}, {"dispatch2", 0400, .seq_ops = &deadline_dispatch2_seq_ops}, + {"owned_by_driver", 0400, dd_owned_by_driver_show}, + {"queued", 0400, dd_queued_show}, {}, }; #undef DEADLINE_QUEUE_DDIR_ATTRS |