From: Jes Sorensen <[email protected]> Put request bytes into 8 buckets of requests, for read, write, and discard.
Enable stats by writing 1 to /sys/block/<dev>/queue/histstat, disable by writing 0. Signed-off-by: Jes Sorensen <[email protected]> --- block/blk-mq.c | 52 ++++++++++++++++++++++++++++++++++++++++++ block/blk-stat.h | 1 + block/blk-sysfs.c | 40 ++++++++++++++++++++++++++++++++ include/linux/blkdev.h | 7 ++++++ 4 files changed, 100 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index 8a59bc0410a6..942ef6e1ed86 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -59,6 +59,52 @@ static int blk_mq_poll_stats_bkt(const struct request *rq) return bucket; } +/* + * 8 buckets for each of read, write, and discard + */ +static int blk_dev_stats_bkt(const struct request *rq) +{ + int grp, bucket; + + grp = op_stat_group(req_op(rq)); + + bucket = grp + 3*(ilog2(rq->io_bytes) - 9); + + if (bucket < 0) + return -1; + else if (bucket >= BLK_DEV_STATS_BKTS) + return grp + BLK_DEV_STATS_BKTS - 3; + + return bucket; +} + +/* + * Copy out the stats to their official location + */ +static void blk_dev_stats_cb(struct blk_stat_callback *cb) +{ + struct request_queue *q = cb->data; + int bucket; + + for (bucket = 0; bucket < BLK_DEV_STATS_BKTS; bucket++) { + if (cb->stat[bucket].nr_samples) { + q->dev_stat[bucket].size += + cb->stat[bucket].size; + q->dev_stat[bucket].nr_samples += + cb->stat[bucket].nr_samples; + } + } + + if (!blk_stat_is_active(cb)) + blk_stat_activate_msecs(cb, 100); +} + +void blk_dev_stats_free(struct request_queue *q) +{ + blk_stat_remove_callback(q, q->dev_cb); + blk_stat_free_callback(q->dev_cb); +} + /* * Check if any of the ctx, dispatch list or elevator * have pending work in this hardware queue. @@ -2881,6 +2927,12 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, if (!q->nr_hw_queues) goto err_hctxs; + q->dev_cb = blk_stat_alloc_callback(blk_dev_stats_cb, + blk_dev_stats_bkt, + BLK_DEV_STATS_BKTS, q); + if (!q->dev_cb) + goto err_hctxs; + INIT_WORK(&q->timeout_work, blk_mq_timeout_work); blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); diff --git a/block/blk-stat.h b/block/blk-stat.h index ea893c4a9af1..7f0c8b737a9d 100644 --- a/block/blk-stat.h +++ b/block/blk-stat.h @@ -168,4 +168,5 @@ void blk_rq_stat_add(struct blk_rq_stat *, u64, u64); void blk_rq_stat_sum(struct blk_rq_stat *, struct blk_rq_stat *); void blk_rq_stat_init(struct blk_rq_stat *); +void blk_dev_stats_free(struct request_queue *q); #endif diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index a16a02c52a85..81566432828d 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -530,6 +530,37 @@ static ssize_t queue_dax_show(struct request_queue *q, char *page) return queue_var_show(blk_queue_dax(q), page); } +static ssize_t queue_histstat_show(struct request_queue *q, char *page) +{ + return queue_var_show(test_bit(QUEUE_FLAG_HISTSTATS, + &q->queue_flags), page); +} + +static ssize_t queue_histstat_store(struct request_queue *q, const char *page, + size_t size) +{ + unsigned long histstat_on; + ssize_t ret; + + ret = queue_var_store(&histstat_on, page, size); + if (ret < 0) + return ret; + + if (histstat_on) { + if (!blk_queue_flag_test_and_set(QUEUE_FLAG_HISTSTATS, q)) + blk_stat_add_callback(q, q->dev_cb); + if (!blk_stat_is_active(q->dev_cb)) + blk_stat_activate_msecs(q->dev_cb, 100); + } else { + if (test_bit(QUEUE_FLAG_HISTSTATS, &q->queue_flags)) { + blk_stat_remove_callback(q, q->dev_cb); + blk_queue_flag_clear(QUEUE_FLAG_HISTSTATS, q); + } + } + + return ret; +} + static struct queue_sysfs_entry queue_requests_entry = { .attr = {.name = "nr_requests", .mode = 0644 }, .show = queue_requests_show, @@ -728,6 +759,12 @@ static struct queue_sysfs_entry throtl_sample_time_entry = { }; #endif +static struct queue_sysfs_entry queue_histstat_entry = { + .attr = {.name = "histstat", .mode = 0644 }, + .show = queue_histstat_show, + .store = queue_histstat_store, +}; + static struct attribute *queue_attrs[] = { &queue_requests_entry.attr, &queue_ra_entry.attr, @@ -767,6 +804,7 @@ static struct attribute *queue_attrs[] = { #ifdef CONFIG_BLK_DEV_THROTTLING_LOW &throtl_sample_time_entry.attr, #endif + &queue_histstat_entry.attr, NULL, }; @@ -856,6 +894,8 @@ static void __blk_release_queue(struct work_struct *work) { struct request_queue *q = container_of(work, typeof(*q), release_work); + blk_dev_stats_free(q); + if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags)) blk_stat_remove_callback(q, q->poll_cb); blk_stat_free_callback(q->poll_cb); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 2716f239b56d..ed57518a15fb 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -53,6 +53,9 @@ struct blk_stat_callback; /* Doing classic polling */ #define BLK_MQ_POLL_CLASSIC -1 +/* Must be consistent with blk_part_stats_bkt() */ +#define BLK_DEV_STATS_BKTS (3 * 8) + /* * Maximum number of blkcg policies allowed to be registered concurrently. * Defined here to simplify include dependency. @@ -478,6 +481,9 @@ struct request_queue { struct blk_stat_callback *poll_cb; struct blk_rq_stat poll_stat[BLK_MQ_POLL_STATS_BKTS]; + struct blk_stat_callback *dev_cb; + struct blk_rq_stat dev_stat[BLK_DEV_STATS_BKTS]; + struct timer_list timeout; struct work_struct timeout_work; @@ -605,6 +611,7 @@ struct request_queue { #define QUEUE_FLAG_SCSI_PASSTHROUGH 23 /* queue supports SCSI commands */ #define QUEUE_FLAG_QUIESCED 24 /* queue has been quiesced */ #define QUEUE_FLAG_PCI_P2PDMA 25 /* device supports PCI p2p requests */ +#define QUEUE_FLAG_HISTSTATS 26 /* Hist stats enabled if set */ #define QUEUE_FLAG_MQ_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_SAME_COMP)) -- 2.17.1
