diff options
Diffstat (limited to 'block/mq-deadline.c')
| -rw-r--r-- | block/mq-deadline.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/block/mq-deadline.c b/block/mq-deadline.c index 94eede4fb9eb..acdc28756d9d 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -488,6 +488,20 @@ unlock: } /* + * 'depth' is a number in the range 1..INT_MAX representing a number of + * requests. Scale it with a factor (1 << bt->sb.shift) / q->nr_requests since + * 1..(1 << bt->sb.shift) is the range expected by sbitmap_get_shallow(). + * Values larger than q->nr_requests have the same effect as q->nr_requests. + */ +static int dd_to_word_depth(struct blk_mq_hw_ctx *hctx, unsigned int qdepth) +{ + struct sbitmap_queue *bt = &hctx->sched_tags->bitmap_tags; + const unsigned int nrr = hctx->queue->nr_requests; + + return ((qdepth << bt->sb.shift) + nrr - 1) / nrr; +} + +/* * Called by __blk_mq_alloc_request(). The shallow_depth value set by this * function is used by __blk_mq_get_tag(). */ @@ -503,7 +517,7 @@ static void dd_limit_depth(blk_opf_t opf, struct blk_mq_alloc_data *data) * Throttle asynchronous requests and writes such that these requests * do not block the allocation of synchronous requests. */ - data->shallow_depth = dd->async_depth; + data->shallow_depth = dd_to_word_depth(data->hctx, dd->async_depth); } /* Called by blk_mq_update_nr_requests(). */ @@ -513,9 +527,9 @@ static void dd_depth_updated(struct blk_mq_hw_ctx *hctx) struct deadline_data *dd = q->elevator->elevator_data; struct blk_mq_tags *tags = hctx->sched_tags; - dd->async_depth = max(1UL, 3 * q->nr_requests / 4); + dd->async_depth = q->nr_requests; - sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, dd->async_depth); + sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, 1); } /* Called by blk_mq_init_hctx() and blk_mq_init_sched(). */ |