blk-mq: allow the driver to pass in a queue mapping
This allows drivers specify their own queue mapping by overriding the
setup-time function that builds the mq_map. This can be used for
example to build the map based on the MSI-X vector mapping provided
by the core interrupt layer for PCI devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index d0634bc..19b1d9c 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -31,14 +31,16 @@
return cpu;
}
-int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues,
- const struct cpumask *online_mask)
+int blk_mq_map_queues(struct blk_mq_tag_set *set)
{
+ unsigned int *map = set->mq_map;
+ unsigned int nr_queues = set->nr_hw_queues;
+ const struct cpumask *online_mask = cpu_online_mask;
unsigned int i, nr_cpus, nr_uniq_cpus, queue, first_sibling;
cpumask_var_t cpus;
if (!alloc_cpumask_var(&cpus, GFP_ATOMIC))
- return 1;
+ return -ENOMEM;
cpumask_clear(cpus);
nr_cpus = nr_uniq_cpus = 0;
@@ -86,23 +88,6 @@
return 0;
}
-unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set)
-{
- unsigned int *map;
-
- /* If cpus are offline, map them to first hctx */
- map = kzalloc_node(sizeof(*map) * nr_cpu_ids, GFP_KERNEL,
- set->numa_node);
- if (!map)
- return NULL;
-
- if (!blk_mq_update_queue_map(map, set->nr_hw_queues, cpu_online_mask))
- return map;
-
- kfree(map);
- return NULL;
-}
-
/*
* We have no quick way of doing reverse lookups. This is only used at
* queue init time, so runtime isn't important.
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 6e077a9..a306007 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2286,6 +2286,8 @@
*/
int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
{
+ int ret;
+
BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS);
if (!set->nr_hw_queues)
@@ -2324,11 +2326,21 @@
if (!set->tags)
return -ENOMEM;
- set->mq_map = blk_mq_make_queue_map(set);
+ ret = -ENOMEM;
+ set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids,
+ GFP_KERNEL, set->numa_node);
if (!set->mq_map)
goto out_free_tags;
- if (blk_mq_alloc_rq_maps(set))
+ if (set->ops->map_queues)
+ ret = set->ops->map_queues(set);
+ else
+ ret = blk_mq_map_queues(set);
+ if (ret)
+ goto out_free_mq_map;
+
+ ret = blk_mq_alloc_rq_maps(set);
+ if (ret)
goto out_free_mq_map;
mutex_init(&set->tag_list_lock);
@@ -2342,7 +2354,7 @@
out_free_tags:
kfree(set->tags);
set->tags = NULL;
- return -ENOMEM;
+ return ret;
}
EXPORT_SYMBOL(blk_mq_alloc_tag_set);
diff --git a/block/blk-mq.h b/block/blk-mq.h
index ec774bf..c92bb7d 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -47,9 +47,7 @@
/*
* CPU -> queue mappings
*/
-extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
-extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues,
- const struct cpumask *online_mask);
+int blk_mq_map_queues(struct blk_mq_tag_set *set);
extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index f01379f..6737fd7 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -104,6 +104,7 @@
bool);
typedef void (busy_tag_iter_fn)(struct request *, void *, bool);
typedef int (poll_fn)(struct blk_mq_hw_ctx *, unsigned int);
+typedef int (map_queues_fn)(struct blk_mq_tag_set *set);
struct blk_mq_ops {
@@ -144,6 +145,8 @@
init_request_fn *init_request;
exit_request_fn *exit_request;
reinit_request_fn *reinit_request;
+
+ map_queues_fn *map_queues;
};
enum {