If the scheduler changes the shallow depth, then return the new depth. No functional changes in this patch.
Signed-off-by: Jens Axboe <[email protected]> --- block/bfq-iosched.c | 13 ++++++++++--- block/kyber-iosched.c | 14 ++++++++++---- include/linux/elevator.h | 2 +- 3 files changed, 21 insertions(+), 8 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index ebc264c87a09..b0dbfd297d20 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -533,19 +533,20 @@ static void bfq_update_depths(struct bfq_data *bfqd, struct sbitmap_queue *bt) * Limit depths of async I/O and sync writes so as to counter both * problems. */ -static void bfq_limit_depth(unsigned int op, struct blk_mq_alloc_data *data) +static int bfq_limit_depth(unsigned int op, struct blk_mq_alloc_data *data) { struct blk_mq_tags *tags = blk_mq_tags_from_data(data); struct bfq_data *bfqd = data->q->elevator->elevator_data; struct sbitmap_queue *bt; + int old_depth; if (op_is_sync(op) && !op_is_write(op)) - return; + return 0; if (data->flags & BLK_MQ_REQ_RESERVED) { if (unlikely(!tags->nr_reserved_tags)) { WARN_ON_ONCE(1); - return; + return 0; } bt = &tags->breserved_tags; } else @@ -554,12 +555,18 @@ static void bfq_limit_depth(unsigned int op, struct blk_mq_alloc_data *data) if (unlikely(bfqd->sb_shift != bt->sb.shift)) bfq_update_depths(bfqd, bt); + old_depth = data->shallow_depth; data->shallow_depth = bfqd->word_depths[!!bfqd->wr_busy_queues][op_is_sync(op)]; bfq_log(bfqd, "[%s] wr_busy %d sync %d depth %u", __func__, bfqd->wr_busy_queues, op_is_sync(op), data->shallow_depth); + + if (old_depth != data->shallow_depth) + return data->shallow_depth; + + return 0; } static struct bfq_queue * diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c index 564967fafe5f..d2622386c115 100644 --- a/block/kyber-iosched.c +++ b/block/kyber-iosched.c @@ -433,17 +433,23 @@ static void rq_clear_domain_token(struct kyber_queue_data *kqd, } } -static void kyber_limit_depth(unsigned int op, struct blk_mq_alloc_data *data) +static int kyber_limit_depth(unsigned int op, struct blk_mq_alloc_data *data) { + struct kyber_queue_data *kqd = data->q->elevator->elevator_data; + + if (op_is_sync(op)) + return 0; + /* * We use the scheduler tags as per-hardware queue queueing tokens. * Async requests can be limited at this stage. */ - if (!op_is_sync(op)) { - struct kyber_queue_data *kqd = data->q->elevator->elevator_data; - + if (data->shallow_depth != kqd->async_depth) { data->shallow_depth = kqd->async_depth; + return data->shallow_depth; } + + return 0; } static void kyber_prepare_request(struct request *rq, struct bio *bio) diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 6d9e230dffd2..b2712f4ca9f1 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -105,7 +105,7 @@ struct elevator_mq_ops { int (*request_merge)(struct request_queue *q, struct request **, struct bio *); void (*request_merged)(struct request_queue *, struct request *, enum elv_merge); void (*requests_merged)(struct request_queue *, struct request *, struct request *); - void (*limit_depth)(unsigned int, struct blk_mq_alloc_data *); + int (*limit_depth)(unsigned int, struct blk_mq_alloc_data *); void (*prepare_request)(struct request *, struct bio *bio); void (*finish_request)(struct request *); void (*insert_requests)(struct blk_mq_hw_ctx *, struct list_head *, bool); -- 2.7.4
