[dm-devel] [PATCH v2 1/3] dm: lower bio-based mempool reservation
Mike Snitzer
snitzer at redhat.com
Fri Sep 13 18:59:38 UTC 2013
Bio-based device mapper processing doesn't need larger mempools (like
request-based DM does), so lower the number of reserved entries for
bio-based operation. 16 was already used for bio-based DM's bioset
but mistakenly wasn't used for it's _io_cache.
Formalize difference between bio-based and request-based defaults by
introducing RESERVED_BIO_BASED_IOS and RESERVED_REQUEST_BASED_IOS.
(based on older code from Mikulas Patocka)
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
Acked-by: Mikulas Patocka <mpatocka at redhat.com>
---
drivers/md/dm.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6a5e9ed..47bac14 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -211,7 +211,8 @@ struct dm_md_mempools {
struct bio_set *bs;
};
-#define MIN_IOS 256
+#define RESERVED_BIO_BASED_IOS 16
+#define RESERVED_REQUEST_BASED_IOS 256
static struct kmem_cache *_io_cache;
static struct kmem_cache *_rq_tio_cache;
@@ -2862,18 +2863,18 @@ struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, u
if (type == DM_TYPE_BIO_BASED) {
cachep = _io_cache;
- pool_size = 16;
+ pool_size = RESERVED_BIO_BASED_IOS;
front_pad = roundup(per_bio_data_size, __alignof__(struct dm_target_io)) + offsetof(struct dm_target_io, clone);
} else if (type == DM_TYPE_REQUEST_BASED) {
cachep = _rq_tio_cache;
- pool_size = MIN_IOS;
+ pool_size = RESERVED_REQUEST_BASED_IOS;
front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
/* per_bio_data_size is not used. See __bind_mempools(). */
WARN_ON(per_bio_data_size != 0);
} else
goto out;
- pools->io_pool = mempool_create_slab_pool(MIN_IOS, cachep);
+ pools->io_pool = mempool_create_slab_pool(pool_size, cachep);
if (!pools->io_pool)
goto out;
--
1.7.1
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