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| author | Jens Axboe <axboe@fb.com> | 2016-03-30 10:21:08 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-11-05 17:09:53 -0600 |
| commit | d278d4a8892f13b6a9eb6102b356402f0e062324 (patch) | |
| tree | 2d1f9dc740b6d47257404c02292493568c8ee656 | |
| parent | 600271d9000027c013c01be87cbb90a5a18c5c3f (diff) | |
| download | linux-d278d4a8892f13b6a9eb6102b356402f0e062324.tar.gz linux-d278d4a8892f13b6a9eb6102b356402f0e062324.tar.bz2 linux-d278d4a8892f13b6a9eb6102b356402f0e062324.zip | |
block: add code to track actual device queue depth
For blk-mq, ->nr_requests does track queue depth, at least at init
time. But for the older queue paths, it's simply a soft setting.
On top of that, it's generally larger than the hardware setting
on purpose, to allow backup of requests for merging.
Fill a hole in struct request with a 'queue_depth' member, that
drivers can call to more closely inform the block layer of the
real queue depth.
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
| -rw-r--r-- | block/blk-settings.c | 12 | ||||
| -rw-r--r-- | drivers/scsi/scsi.c | 3 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 11 |
3 files changed, 26 insertions, 0 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 55369a65dea2..9cf053759363 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -837,6 +837,18 @@ void blk_queue_flush_queueable(struct request_queue *q, bool queueable) EXPORT_SYMBOL_GPL(blk_queue_flush_queueable); /** + * blk_set_queue_depth - tell the block layer about the device queue depth + * @q: the request queue for the device + * @depth: queue depth + * + */ +void blk_set_queue_depth(struct request_queue *q, unsigned int depth) +{ + q->queue_depth = depth; +} +EXPORT_SYMBOL(blk_set_queue_depth); + +/** * blk_queue_write_cache - configure queue's write cache * @q: the request queue for the device * @wc: write back cache on or off diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 1deb6adc411f..75455d4dab68 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -621,6 +621,9 @@ int scsi_change_queue_depth(struct scsi_device *sdev, int depth) wmb(); } + if (sdev->request_queue) + blk_set_queue_depth(sdev->request_queue, depth); + return sdev->queue_depth; } EXPORT_SYMBOL(scsi_change_queue_depth); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 9189a2d5c392..d364be6e6959 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -405,6 +405,8 @@ struct request_queue { struct blk_mq_ctx __percpu *queue_ctx; unsigned int nr_queues; + unsigned int queue_depth; + /* hw dispatch queues */ struct blk_mq_hw_ctx **queue_hw_ctx; unsigned int nr_hw_queues; @@ -777,6 +779,14 @@ static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) return false; } +static inline unsigned int blk_queue_depth(struct request_queue *q) +{ + if (q->queue_depth) + return q->queue_depth; + + return q->nr_requests; +} + /* * q->prep_rq_fn return values */ @@ -1094,6 +1104,7 @@ extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min); extern void blk_queue_io_min(struct request_queue *q, unsigned int min); extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt); extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); +extern void blk_set_queue_depth(struct request_queue *q, unsigned int depth); extern void blk_set_default_limits(struct queue_limits *lim); extern void blk_set_stacking_limits(struct queue_limits *lim); extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, |