@@ -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 +845,9 @@ static void __exit null_exit(void)
null_del_dev(nullb);
}
mutex_unlock(&lock);
+
+ if (use_lightnvm)
+ kmem_cache_destroy(ppa_cache);
}
module_init(null_init);
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: Matias Bjørling <m@bjorling.me> --- drivers/block/null_blk.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-)