From a4391c6465d9c978fd4bded12e34bdde3f5458f0 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 5 Jun 2014 15:21:56 -0600 Subject: [PATCH] blk-mq: bump max tag depth to 10K tags For some scsi-mq cases, the tag map can be huge. So increase the max number of tags we support. Additionally, don't fail with EINVAL if a user requests too many tags. Warn that the tag depth has been adjusted down, and store the new value inside the tag_set passed in. Signed-off-by: Jens Axboe --- block/blk-mq.c | 13 ++++++++++++- include/linux/blk-mq.h | 2 +- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 4e4cd62..a6ee74e2 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1967,13 +1967,19 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb, return NOTIFY_OK; } +/* + * Alloc a tag set to be associated with one or more request queues. + * May fail with EINVAL for various error conditions. May adjust the + * requested depth down, if if it too large. In that case, the set + * value will be stored in set->queue_depth. + */ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) { int i; if (!set->nr_hw_queues) return -EINVAL; - if (!set->queue_depth || set->queue_depth > BLK_MQ_MAX_DEPTH) + if (!set->queue_depth) return -EINVAL; if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) return -EINVAL; @@ -1981,6 +1987,11 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) if (!set->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue) return -EINVAL; + if (set->queue_depth > BLK_MQ_MAX_DEPTH) { + pr_info("blk-mq: reduced tag depth to %u\n", + BLK_MQ_MAX_DEPTH); + set->queue_depth = BLK_MQ_MAX_DEPTH; + } set->tags = kmalloc_node(set->nr_hw_queues * sizeof(struct blk_mq_tags *), diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 0feedeb..a002cf1 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -135,7 +135,7 @@ enum { BLK_MQ_S_STOPPED = 0, BLK_MQ_S_TAG_ACTIVE = 1, - BLK_MQ_MAX_DEPTH = 2048, + BLK_MQ_MAX_DEPTH = 10240, BLK_MQ_CPU_WORK_BATCH = 8, }; -- 2.7.4