Do not allocate the io_pool mempool for blk-mq request-based DM
(DM_TYPE_MQ_REQUEST_BASED) in dm_alloc_rq_mempools().
Also refine __bind_mempools() to have more precise awareness of which
mempools each type of DM device uses -- avoids mempool churn when
reloading DM tables (particularly for DM_TYPE_REQUEST_BASED).
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
drivers/md/dm-table.c | 4 +--
drivers/md/dm.c | 69 ++++++++++++++++++++++++++++-----------------------
2 files changed, 40 insertions(+), 33 deletions(-)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 3662b2e..2000fea 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -962,8 +962,8 @@ static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *
return -EINVAL;
}
- if (!t->mempools)
- return -ENOMEM;
+ if (IS_ERR(t->mempools))
+ return PTR_ERR(t->mempools);
return 0;
}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 38837f8..8502da7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2317,39 +2317,52 @@ static void free_dev(struct mapped_device *md)
kfree(md);
}
+static unsigned filter_md_type(unsigned type, struct mapped_device *md)
+{
+ if (type == DM_TYPE_BIO_BASED)
+ return type;
+
+ return !md->use_blk_mq ? DM_TYPE_REQUEST_BASED : DM_TYPE_MQ_REQUEST_BASED;
+}
+
static void __bind_mempools(struct mapped_device *md, struct dm_table *t)
{
struct dm_md_mempools *p = dm_table_get_md_mempools(t);
- if (md->bs) {
- /* The md already has necessary mempools. */
- if (dm_table_get_type(t) == DM_TYPE_BIO_BASED) {
+ switch (filter_md_type(dm_table_get_type(t), md)) {
+ case DM_TYPE_BIO_BASED:
+ if (md->bs && md->io_pool) {
/*
+ * This bio-based md already has necessary mempools.
* Reload bioset because front_pad may have changed
* because a different table was loaded.
*/
bioset_free(md->bs);
md->bs = p->bs;
p->bs = NULL;
+ goto out;
}
- /*
- * There's no need to reload with request-based dm
- * because the size of front_pad doesn't change.
- * Note for future: If you are to reload bioset,
- * prep-ed requests in the queue may refer
- * to bio from the old bioset, so you must walk
- * through the queue to unprep.
- */
- goto out;
+ break;
+ case DM_TYPE_REQUEST_BASED:
+ if (md->rq_pool && md->io_pool)
+ /*
+ * This request-based md already has necessary mempools.
+ */
+ goto out;
+ break;
+ case DM_TYPE_MQ_REQUEST_BASED:
+ BUG_ON(p); /* No mempools needed */
+ return;
}
+ BUG_ON(!p || md->io_pool || md->rq_pool || md->bs);
+
md->io_pool = p->io_pool;
p->io_pool = NULL;
md->rq_pool = p->rq_pool;
p->rq_pool = NULL;
md->bs = p->bs;
p->bs = NULL;
-
out:
/* mempool bind completed, no longer need any mempools in the table */
dm_table_free_md_mempools(t);
@@ -2726,14 +2739,6 @@ out_tag_set:
return err;
}
-static unsigned filter_md_type(unsigned type, struct mapped_device *md)
-{
- if (type == DM_TYPE_BIO_BASED)
- return type;
-
- return !md->use_blk_mq ? DM_TYPE_REQUEST_BASED : DM_TYPE_MQ_REQUEST_BASED;
-}
-
/*
* Setup the DM device's queue based on md's type
*/
@@ -3455,7 +3460,7 @@ struct dm_md_mempools *dm_alloc_bio_mempools(unsigned integrity,
pools = kzalloc(sizeof(*pools), GFP_KERNEL);
if (!pools)
- return NULL;
+ return ERR_PTR(-ENOMEM);
front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) +
offsetof(struct dm_target_io, clone);
@@ -3474,24 +3479,26 @@ struct dm_md_mempools *dm_alloc_bio_mempools(unsigned integrity,
return pools;
out:
dm_free_md_mempools(pools);
- return NULL;
+ return ERR_PTR(-ENOMEM);
}
struct dm_md_mempools *dm_alloc_rq_mempools(struct mapped_device *md,
unsigned type)
{
- unsigned int pool_size = dm_get_reserved_rq_based_ios();
+ unsigned int pool_size;
struct dm_md_mempools *pools;
+ if (filter_md_type(type, md) == DM_TYPE_MQ_REQUEST_BASED)
+ return NULL; /* No mempools needed */
+
+ pool_size = dm_get_reserved_rq_based_ios();
pools = kzalloc(sizeof(*pools), GFP_KERNEL);
if (!pools)
- return NULL;
+ return ERR_PTR(-ENOMEM);
- if (filter_md_type(type, md) == DM_TYPE_REQUEST_BASED) {
- pools->rq_pool = mempool_create_slab_pool(pool_size, _rq_cache);
- if (!pools->rq_pool)
- goto out;
- }
+ pools->rq_pool = mempool_create_slab_pool(pool_size, _rq_cache);
+ if (!pools->rq_pool)
+ goto out;
pools->io_pool = mempool_create_slab_pool(pool_size, _rq_tio_cache);
if (!pools->io_pool)
@@ -3500,7 +3507,7 @@ struct dm_md_mempools *dm_alloc_rq_mempools(struct mapped_device *md,
return pools;
out:
dm_free_md_mempools(pools);
- return NULL;
+ return ERR_PTR(-ENOMEM);
}
void dm_free_md_mempools(struct dm_md_mempools *pools)
--
2.3.2 (Apple Git-55)
--
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