Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6bb9535b authored by Matias Bjørling's avatar Matias Bjørling Committed by Jens Axboe
Browse files

null_blk: use ppa_cache pool 



Instead of using a page pool, we can save memory by only allocating room
for 64 entries for the ppa command. Introduce a ppa_cache to allocate only
the required memory for the ppa list.

Signed-off-by: default avatarMatias Bjørling <m@bjorling.me>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 6824c5ef

drivers/block/null_blk.c

+23 −2
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ static LIST_HEAD(nullb_list); 
static struct mutex lock;

static int null_major;

static int nullb_indexes;

static struct kmem_cache *ppa_cache;



struct completion_queue {

	struct llist_head list;
@@ -521,7 +522,7 @@ static void *null_lnvm_create_dma_pool(struct request_queue *q, char *name) 
{

	mempool_t *virtmem_pool;



	virtmem_pool = mempool_create_page_pool(64, 0);

	virtmem_pool = mempool_create_slab_pool(64, ppa_cache);

	if (!virtmem_pool) {

		pr_err("null_blk: Unable to create virtual memory pool\n");

		return NULL;
@@ -767,6 +768,12 @@ static int __init null_init(void) 
		bs = PAGE_SIZE;

	}



	if (use_lightnvm && bs != 4096) {

		pr_warn("null_blk: LightNVM only supports 4k block size\n");

		pr_warn("null_blk: defaults block size to 4k\n");

		bs = 4096;

	}



	if (use_lightnvm && queue_mode != NULL_Q_MQ) {

		pr_warn("null_blk: LightNVM only supported for blk-mq\n");

		pr_warn("null_blk: defaults queue mode to blk-mq\n");
@@ -803,15 +810,27 @@ static int __init null_init(void) 
	if (null_major < 0)

		return null_major;



	if (use_lightnvm) {

		ppa_cache = kmem_cache_create("ppa_cache", 64 * sizeof(u64),

								0, 0, NULL);

		if (!ppa_cache) {

			pr_err("null_blk: unable to create ppa cache\n");

			return -ENOMEM;

		}

	}



	for (i = 0; i < nr_devices; i++) {

		if (null_add_dev()) {

			unregister_blkdev(null_major, "nullb");

			return -EINVAL;

			goto err_ppa;

		}

	}



	pr_info("null: module loaded\n");

	return 0;

err_ppa:

	kmem_cache_destroy(ppa_cache);

	return -EINVAL;

}



static void __exit null_exit(void)
@@ -826,6 +845,8 @@ static void __exit null_exit(void) 
		null_del_dev(nullb);

	}

	mutex_unlock(&lock);



	kmem_cache_destroy(ppa_cache);

}



module_init(null_init);