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-rw-r--r--drivers/md/dm.c71
1 files changed, 67 insertions, 4 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6a5e9ed2fcc3..b3e26c7d1417 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -211,10 +211,55 @@ struct dm_md_mempools {
struct bio_set *bs;
};
-#define MIN_IOS 256
+#define RESERVED_BIO_BASED_IOS 16
+#define RESERVED_REQUEST_BASED_IOS 256
+#define RESERVED_MAX_IOS 1024
static struct kmem_cache *_io_cache;
static struct kmem_cache *_rq_tio_cache;
+/*
+ * Bio-based DM's mempools' reserved IOs set by the user.
+ */
+static unsigned reserved_bio_based_ios = RESERVED_BIO_BASED_IOS;
+
+/*
+ * Request-based DM's mempools' reserved IOs set by the user.
+ */
+static unsigned reserved_rq_based_ios = RESERVED_REQUEST_BASED_IOS;
+
+static unsigned __dm_get_reserved_ios(unsigned *reserved_ios,
+ unsigned def, unsigned max)
+{
+ unsigned ios = ACCESS_ONCE(*reserved_ios);
+ unsigned modified_ios = 0;
+
+ if (!ios)
+ modified_ios = def;
+ else if (ios > max)
+ modified_ios = max;
+
+ if (modified_ios) {
+ (void)cmpxchg(reserved_ios, ios, modified_ios);
+ ios = modified_ios;
+ }
+
+ return ios;
+}
+
+unsigned dm_get_reserved_bio_based_ios(void)
+{
+ return __dm_get_reserved_ios(&reserved_bio_based_ios,
+ RESERVED_BIO_BASED_IOS, RESERVED_MAX_IOS);
+}
+EXPORT_SYMBOL_GPL(dm_get_reserved_bio_based_ios);
+
+unsigned dm_get_reserved_rq_based_ios(void)
+{
+ return __dm_get_reserved_ios(&reserved_rq_based_ios,
+ RESERVED_REQUEST_BASED_IOS, RESERVED_MAX_IOS);
+}
+EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios);
+
static int __init local_init(void)
{
int r = -ENOMEM;
@@ -2278,6 +2323,17 @@ struct target_type *dm_get_immutable_target_type(struct mapped_device *md)
}
/*
+ * The queue_limits are only valid as long as you have a reference
+ * count on 'md'.
+ */
+struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
+{
+ BUG_ON(!atomic_read(&md->holders));
+ return &md->queue->limits;
+}
+EXPORT_SYMBOL_GPL(dm_get_queue_limits);
+
+/*
* Fully initialize a request-based queue (->elevator, ->request_fn, etc).
*/
static int dm_init_request_based_queue(struct mapped_device *md)
@@ -2862,18 +2918,18 @@ 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 = dm_get_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 = dm_get_reserved_rq_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;
@@ -2924,6 +2980,13 @@ module_exit(dm_exit);
module_param(major, uint, 0);
MODULE_PARM_DESC(major, "The major number of the device mapper");
+
+module_param(reserved_bio_based_ios, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(reserved_bio_based_ios, "Reserved IOs in bio-based mempools");
+
+module_param(reserved_rq_based_ios, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(reserved_rq_based_ios, "Reserved IOs in request-based mempools");
+
MODULE_DESCRIPTION(DM_NAME " driver");
MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
MODULE_LICENSE("GPL");