Ensure that depth of a queue is enough to hold at least reserved tags plus a minimal amount of normal tags. The minimal amount is chosen to be consistent with minimal length of tags cache.
Signed-off-by: Alexander Gordeev <[email protected]> --- block/blk-mq-tag.c | 8 ++++---- block/blk-mq-tag.h | 6 ++++++ block/blk-mq.c | 12 +++++++----- 3 files changed, 17 insertions(+), 9 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 6718007..fe4acb1 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -447,10 +447,10 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, tags->nr_tags = nr_tags; tags->reserved_tags = reserved_tags; tags->max_cache = nr_tags / num_possible_cpus(); - if (tags->max_cache < 4) - tags->max_cache = 4; - else if (tags->max_cache > 64) - tags->max_cache = 64; + if (tags->max_cache < BLK_MQ_TAG_CACHE_MIN) + tags->max_cache = BLK_MQ_TAG_CACHE_MIN; + else if (tags->max_cache > BLK_MQ_TAG_CACHE_MAX) + tags->max_cache = BLK_MQ_TAG_CACHE_MAX; tags->batch_move = tags->max_cache / 2; diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index ce4d5b2..716ea79 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -14,7 +14,13 @@ extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags); extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page); enum { + BLK_MQ_TAG_CACHE_MIN = 4, + BLK_MQ_TAG_CACHE_MAX = 64, +}; + +enum { BLK_MQ_TAG_FAIL = -1U, + BLK_MQ_TAG_MIN = BLK_MQ_TAG_CACHE_MIN, BLK_MQ_TAG_MAX = BLK_MQ_TAG_FAIL - 1, }; diff --git a/block/blk-mq.c b/block/blk-mq.c index 6fc1df3..a8b4c79 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1151,8 +1151,8 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx, } } - if (!i) - return -ENOMEM; + if (i < (reserved_tags + BLK_MQ_TAG_MIN)) + goto err_rq_map; else if (i != hctx->queue_depth) { hctx->queue_depth = i; pr_warn("%s: queue depth set to %u because of low memory\n", @@ -1161,6 +1161,7 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx, hctx->tags = blk_mq_init_tags(hctx->queue_depth, reserved_tags, node); if (!hctx->tags) { +err_rq_map: blk_mq_free_rq_map(hctx); return -ENOMEM; } @@ -1305,9 +1306,10 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg, struct request_queue *q; int i; - if (!reg->nr_hw_queues || !reg->ops->queue_rq || - !reg->ops->map_queue || !reg->ops->alloc_hctx || - !reg->ops->free_hctx) + if (!reg->nr_hw_queues || + !reg->ops->queue_rq || !reg->ops->map_queue || + !reg->ops->alloc_hctx || !reg->ops->free_hctx || + (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN))) return ERR_PTR(-EINVAL); if (!reg->queue_depth) -- 1.7.7.6 -- Regards, Alexander Gordeev [email protected] -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
