From 6bb9535bc3f59194a0ae17b17ca71aecd0f7e3a2 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Matias=20Bj=C3=B8rling?= Date: Thu, 19 Nov 2015 12:50:08 +0100 Subject: [PATCH] null_blk: use ppa_cache pool MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Jens Axboe --- drivers/block/null_blk.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 816525143a74..3e9c4f94b5be 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -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); -- 2.39.2