dm mpath: use blk-mq pdu for per-request 'struct dm_mpath_io'
Allow the multipath target to avoid making small allocations for each
'struct dm_mpath_io' that is needed for each request.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index fde08c98..5b06a94 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -181,10 +181,9 @@
kfree(pg);
}
-static struct multipath *alloc_multipath(struct dm_target *ti)
+static struct multipath *alloc_multipath(struct dm_target *ti, bool use_blk_mq)
{
struct multipath *m;
- unsigned min_ios = dm_get_reserved_rq_based_ios();
m = kzalloc(sizeof(*m), GFP_KERNEL);
if (m) {
@@ -195,11 +194,18 @@
INIT_WORK(&m->trigger_event, trigger_event);
init_waitqueue_head(&m->pg_init_wait);
mutex_init(&m->work_mutex);
- m->mpio_pool = mempool_create_slab_pool(min_ios, _mpio_cache);
- if (!m->mpio_pool) {
- kfree(m);
- return NULL;
+
+ m->mpio_pool = NULL;
+ if (!use_blk_mq) {
+ unsigned min_ios = dm_get_reserved_rq_based_ios();
+
+ m->mpio_pool = mempool_create_slab_pool(min_ios, _mpio_cache);
+ if (!m->mpio_pool) {
+ kfree(m);
+ return NULL;
+ }
}
+
m->ti = ti;
ti->private = m;
}
@@ -226,6 +232,13 @@
{
struct dm_mpath_io *mpio;
+ if (!m->mpio_pool) {
+ /* Use blk-mq pdu memory requested via per_io_data_size */
+ mpio = info->ptr;
+ memset(mpio, 0, sizeof(*mpio));
+ return mpio;
+ }
+
mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC);
if (!mpio)
return -ENOMEM;
@@ -238,10 +251,13 @@
static void clear_mapinfo(struct multipath *m, union map_info *info)
{
- struct dm_mpath_io *mpio = info->ptr;
+ /* Only needed for non blk-mq */
+ if (m->mpio_pool) {
+ struct dm_mpath_io *mpio = info->ptr;
- info->ptr = NULL;
- mempool_free(mpio, m->mpio_pool);
+ info->ptr = NULL;
+ mempool_free(mpio, m->mpio_pool);
+ }
}
/*-----------------------------------------------
@@ -827,11 +843,12 @@
struct dm_arg_set as;
unsigned pg_count = 0;
unsigned next_pg_num;
+ bool use_blk_mq = dm_use_blk_mq(dm_table_get_md(ti->table));
as.argc = argc;
as.argv = argv;
- m = alloc_multipath(ti);
+ m = alloc_multipath(ti, use_blk_mq);
if (!m) {
ti->error = "can't allocate multipath";
return -EINVAL;
@@ -887,6 +904,8 @@
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->num_write_same_bios = 1;
+ if (use_blk_mq)
+ ti->per_io_data_size = sizeof(struct dm_mpath_io);
return 0;