diff options
| -rw-r--r-- | block/blk-core.c | 41 | ||||
| -rw-r--r-- | block/blk-mq-sysfs.c | 10 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 35 | ||||
| -rw-r--r-- | include/linux/blk-mq.h | 10 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 3 |
5 files changed, 99 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index e93df6d386a0..fa36b4ff7d63 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -3312,6 +3312,47 @@ void blk_finish_plug(struct blk_plug *plug) } EXPORT_SYMBOL(blk_finish_plug); +bool blk_poll(struct request_queue *q, blk_qc_t cookie) +{ + struct blk_plug *plug; + long state; + + if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) || + !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) + return false; + + plug = current->plug; + if (plug) + blk_flush_plug_list(plug, false); + + state = current->state; + while (!need_resched()) { + unsigned int queue_num = blk_qc_t_to_queue_num(cookie); + struct blk_mq_hw_ctx *hctx = q->queue_hw_ctx[queue_num]; + int ret; + + hctx->poll_invoked++; + + ret = q->mq_ops->poll(hctx, blk_qc_t_to_tag(cookie)); + if (ret > 0) { + hctx->poll_success++; + set_current_state(TASK_RUNNING); + return true; + } + + if (signal_pending_state(state, current)) + set_current_state(TASK_RUNNING); + + if (current->state == TASK_RUNNING) + return true; + if (ret < 0) + break; + cpu_relax(); + } + + return false; +} + #ifdef CONFIG_PM /** * blk_pm_runtime_init - Block layer runtime PM initialization routine diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 6f57a110289c..1cf18784c5cf 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -174,6 +174,11 @@ static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page) return ret; } +static ssize_t blk_mq_hw_sysfs_poll_show(struct blk_mq_hw_ctx *hctx, char *page) +{ + return sprintf(page, "invoked=%lu, success=%lu\n", hctx->poll_invoked, hctx->poll_success); +} + static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx, char *page) { @@ -295,6 +300,10 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = { .attr = {.name = "cpu_list", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_cpus_show, }; +static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = { + .attr = {.name = "io_poll", .mode = S_IRUGO }, + .show = blk_mq_hw_sysfs_poll_show, +}; static struct attribute *default_hw_ctx_attrs[] = { &blk_mq_hw_sysfs_queued.attr, @@ -304,6 +313,7 @@ static struct attribute *default_hw_ctx_attrs[] = { &blk_mq_hw_sysfs_tags.attr, &blk_mq_hw_sysfs_cpus.attr, &blk_mq_hw_sysfs_active.attr, + &blk_mq_hw_sysfs_poll.attr, NULL, }; diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 31849e328b45..565b8dac5782 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -317,6 +317,34 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) return ret; } +static ssize_t queue_poll_show(struct request_queue *q, char *page) +{ + return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page); +} + +static ssize_t queue_poll_store(struct request_queue *q, const char *page, + size_t count) +{ + unsigned long poll_on; + ssize_t ret; + + if (!q->mq_ops || !q->mq_ops->poll) + return -EINVAL; + + ret = queue_var_store(&poll_on, page, count); + if (ret < 0) + return ret; + + spin_lock_irq(q->queue_lock); + if (poll_on) + queue_flag_set(QUEUE_FLAG_POLL, q); + else + queue_flag_clear(QUEUE_FLAG_POLL, q); + spin_unlock_irq(q->queue_lock); + + return ret; +} + static struct queue_sysfs_entry queue_requests_entry = { .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, .show = queue_requests_show, @@ -442,6 +470,12 @@ static struct queue_sysfs_entry queue_random_entry = { .store = queue_store_random, }; +static struct queue_sysfs_entry queue_poll_entry = { + .attr = {.name = "io_poll", .mode = S_IRUGO | S_IWUSR }, + .show = queue_poll_show, + .store = queue_poll_store, +}; + static struct attribute *default_attrs[] = { &queue_requests_entry.attr, &queue_ra_entry.attr, @@ -466,6 +500,7 @@ static struct attribute *default_attrs[] = { &queue_rq_affinity_entry.attr, &queue_iostats_entry.attr, &queue_random_entry.attr, + &queue_poll_entry.attr, NULL, }; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 83cc9d4e5455..daf17d70aeca 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -59,6 +59,9 @@ struct blk_mq_hw_ctx { struct blk_mq_cpu_notifier cpu_notifier; struct kobject kobj; + + unsigned long poll_invoked; + unsigned long poll_success; }; struct blk_mq_tag_set { @@ -97,6 +100,8 @@ typedef void (exit_request_fn)(void *, struct request *, unsigned int, typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *, bool); typedef void (busy_tag_iter_fn)(struct request *, void *, bool); +typedef int (poll_fn)(struct blk_mq_hw_ctx *, unsigned int); + struct blk_mq_ops { /* @@ -114,6 +119,11 @@ struct blk_mq_ops { */ timeout_fn *timeout; + /* + * Called to poll for completion of a specific tag. + */ + poll_fn *poll; + softirq_done_fn *complete; /* diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5ee0f5243025..3fe27f8d91f0 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -487,6 +487,7 @@ struct request_queue { #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ +#define QUEUE_FLAG_POLL 22 /* IO polling enabled if set */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_STACKABLE) | \ @@ -814,6 +815,8 @@ extern int blk_execute_rq(struct request_queue *, struct gendisk *, extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *, struct request *, int, rq_end_io_fn *); +bool blk_poll(struct request_queue *q, blk_qc_t cookie); + static inline struct request_queue *bdev_get_queue(struct block_device *bdev) { return bdev->bd_disk->queue; /* this is never NULL */ |