[dm-devel] [dm-4.6 PATCH v2 08/15] dm: allocate blk_mq_tag_set rather than embed in mapped_device
Mike Snitzer
snitzer at redhat.com
Sun Feb 7 15:53:30 UTC 2016
The blk_mq_tag_set is only needed for dm-mq support. There is point
wasting space in 'struct mapped_device' for non-dm-mq devices.
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
---
drivers/md/dm.c | 42 ++++++++++++++++++++++++------------------
1 file changed, 24 insertions(+), 18 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ec505e5..1fab790 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -223,7 +223,7 @@ struct mapped_device {
ktime_t last_rq_start_time;
/* for blk-mq request-based DM support */
- struct blk_mq_tag_set tag_set;
+ struct blk_mq_tag_set *tag_set;
bool use_blk_mq;
};
@@ -2386,8 +2386,10 @@ static void free_dev(struct mapped_device *md)
unlock_fs(md);
cleanup_mapped_device(md);
- if (md->use_blk_mq)
- blk_mq_free_tag_set(&md->tag_set);
+ if (md->tag_set) {
+ blk_mq_free_tag_set(md->tag_set);
+ kfree(md->tag_set);
+ }
free_table_devices(&md->table_devices);
dm_stats_cleanup(&md->stats);
@@ -2708,24 +2710,25 @@ static int dm_init_request_based_blk_mq_queue(struct mapped_device *md)
struct request_queue *q;
int err;
- memset(&md->tag_set, 0, sizeof(md->tag_set));
- md->tag_set.ops = &dm_mq_ops;
- md->tag_set.queue_depth = dm_get_blk_mq_queue_depth();
- md->tag_set.numa_node = NUMA_NO_NODE;
- md->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
- md->tag_set.nr_hw_queues = dm_get_blk_mq_nr_hw_queues();
+ md->tag_set = kzalloc(sizeof(struct blk_mq_tag_set), GFP_KERNEL);
+ md->tag_set->ops = &dm_mq_ops;
+ md->tag_set->queue_depth = dm_get_blk_mq_queue_depth();
+ md->tag_set->numa_node = NUMA_NO_NODE;
+ md->tag_set->flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+ md->tag_set->nr_hw_queues = dm_get_blk_mq_nr_hw_queues();
+ md->tag_set->driver_data = md;
+
+ md->tag_set->cmd_size = sizeof(struct dm_rq_target_io);
if (md_type == DM_TYPE_REQUEST_BASED) {
- /* make the memory for non-blk-mq clone part of the pdu */
- md->tag_set.cmd_size = sizeof(struct dm_rq_target_io) + sizeof(struct request);
- } else
- md->tag_set.cmd_size = sizeof(struct dm_rq_target_io);
- md->tag_set.driver_data = md;
+ /* put the memory for non-blk-mq clone at the end of the pdu */
+ md->tag_set->cmd_size += sizeof(struct request);
+ }
- err = blk_mq_alloc_tag_set(&md->tag_set);
+ err = blk_mq_alloc_tag_set(md->tag_set);
if (err)
- return err;
+ goto out_kfree_tag_set;
- q = blk_mq_init_allocated_queue(&md->tag_set, md->queue);
+ q = blk_mq_init_allocated_queue(md->tag_set, md->queue);
if (IS_ERR(q)) {
err = PTR_ERR(q);
goto out_tag_set;
@@ -2742,7 +2745,10 @@ static int dm_init_request_based_blk_mq_queue(struct mapped_device *md)
return 0;
out_tag_set:
- blk_mq_free_tag_set(&md->tag_set);
+ blk_mq_free_tag_set(md->tag_set);
+out_kfree_tag_set:
+ kfree(md->tag_set);
+
return err;
}
--
2.5.4 (Apple Git-61)
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