blk-mq: Shared tag enhancements

Storage controllers may expose multiple block devices that share hardware
resources managed by blk-mq. This patch enhances the shared tags so a
low-level driver can access the shared resources not tied to the unshared
h/w contexts. This way the LLD can dynamically add and delete disks and
request queues without having to track all the request_queue hctx's to
iterate outstanding tags.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Keith Busch
2015-06-01 09:29:53 -06:00
committed by Jens Axboe
parent e548ca4ee4
commit f26cdc8536
4 changed files with 53 additions and 2 deletions
+10 -2
View File
@@ -1525,7 +1525,6 @@ static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
i++;
}
}
return tags;
fail:
@@ -1821,6 +1820,7 @@ static void blk_mq_map_swqueue(struct request_queue *q)
hctx = q->mq_ops->map_queue(q, i);
cpumask_set_cpu(i, hctx->cpumask);
cpumask_set_cpu(i, hctx->tags->cpumask);
ctx->index_hw = hctx->nr_ctx;
hctx->ctxs[hctx->nr_ctx++] = ctx;
}
@@ -2187,6 +2187,12 @@ static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
return 0;
}
struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags)
{
return tags->cpumask;
}
EXPORT_SYMBOL_GPL(blk_mq_tags_cpumask);
/*
* Alloc a tag set to be associated with one or more request queues.
* May fail with EINVAL for various error conditions. May adjust the
@@ -2248,8 +2254,10 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
int i;
for (i = 0; i < set->nr_hw_queues; i++) {
if (set->tags[i])
if (set->tags[i]) {
blk_mq_free_rq_map(set, set->tags[i], i);
free_cpumask_var(set->tags[i]->cpumask);
}
}
kfree(set->tags);