lightnvm: pblk: stop recreating global caches

Pblk should not create a set of global caches every time
a pblk instance is created. The global caches should be
made available only when there is one or more pblk instances.

This patch bundles the global caches together with a kref
keeping track of whether the caches should be available or not.

Also, turn the global pblk lock into a mutex that explicitly
protects the caches (as this was the only purpose of the lock).

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Hans Holmberg 2018-10-09 13:11:58 +02:00 committed by Jens Axboe
parent 63dee3a6c3
commit 1864de94ec

View File

@ -26,9 +26,24 @@ static unsigned int write_buffer_size;
module_param(write_buffer_size, uint, 0644);
MODULE_PARM_DESC(write_buffer_size, "number of entries in a write buffer");
static struct kmem_cache *pblk_ws_cache, *pblk_rec_cache, *pblk_g_rq_cache,
*pblk_w_rq_cache;
static DECLARE_RWSEM(pblk_lock);
struct pblk_global_caches {
struct kmem_cache *ws;
struct kmem_cache *rec;
struct kmem_cache *g_rq;
struct kmem_cache *w_rq;
struct kref kref;
struct mutex mutex; /* Ensures consistency between
* caches and kref
*/
};
static struct pblk_global_caches pblk_caches = {
.mutex = __MUTEX_INITIALIZER(pblk_caches.mutex),
.kref = KREF_INIT(0),
};
struct bio_set pblk_bio_set;
static int pblk_rw_io(struct request_queue *q, struct pblk *pblk,
@ -307,53 +322,80 @@ static int pblk_set_addrf(struct pblk *pblk)
return 0;
}
static int pblk_init_global_caches(struct pblk *pblk)
static int pblk_create_global_caches(void)
{
down_write(&pblk_lock);
pblk_ws_cache = kmem_cache_create("pblk_blk_ws",
pblk_caches.ws = kmem_cache_create("pblk_blk_ws",
sizeof(struct pblk_line_ws), 0, 0, NULL);
if (!pblk_ws_cache) {
up_write(&pblk_lock);
if (!pblk_caches.ws)
return -ENOMEM;
}
pblk_rec_cache = kmem_cache_create("pblk_rec",
pblk_caches.rec = kmem_cache_create("pblk_rec",
sizeof(struct pblk_rec_ctx), 0, 0, NULL);
if (!pblk_rec_cache) {
kmem_cache_destroy(pblk_ws_cache);
up_write(&pblk_lock);
return -ENOMEM;
}
if (!pblk_caches.rec)
goto fail_destroy_ws;
pblk_g_rq_cache = kmem_cache_create("pblk_g_rq", pblk_g_rq_size,
pblk_caches.g_rq = kmem_cache_create("pblk_g_rq", pblk_g_rq_size,
0, 0, NULL);
if (!pblk_g_rq_cache) {
kmem_cache_destroy(pblk_ws_cache);
kmem_cache_destroy(pblk_rec_cache);
up_write(&pblk_lock);
return -ENOMEM;
}
if (!pblk_caches.g_rq)
goto fail_destroy_rec;
pblk_w_rq_cache = kmem_cache_create("pblk_w_rq", pblk_w_rq_size,
pblk_caches.w_rq = kmem_cache_create("pblk_w_rq", pblk_w_rq_size,
0, 0, NULL);
if (!pblk_w_rq_cache) {
kmem_cache_destroy(pblk_ws_cache);
kmem_cache_destroy(pblk_rec_cache);
kmem_cache_destroy(pblk_g_rq_cache);
up_write(&pblk_lock);
return -ENOMEM;
}
up_write(&pblk_lock);
if (!pblk_caches.w_rq)
goto fail_destroy_g_rq;
return 0;
fail_destroy_g_rq:
kmem_cache_destroy(pblk_caches.g_rq);
fail_destroy_rec:
kmem_cache_destroy(pblk_caches.rec);
fail_destroy_ws:
kmem_cache_destroy(pblk_caches.ws);
return -ENOMEM;
}
static void pblk_free_global_caches(struct pblk *pblk)
static int pblk_get_global_caches(void)
{
kmem_cache_destroy(pblk_ws_cache);
kmem_cache_destroy(pblk_rec_cache);
kmem_cache_destroy(pblk_g_rq_cache);
kmem_cache_destroy(pblk_w_rq_cache);
int ret;
mutex_lock(&pblk_caches.mutex);
if (kref_read(&pblk_caches.kref) > 0) {
kref_get(&pblk_caches.kref);
mutex_unlock(&pblk_caches.mutex);
return 0;
}
ret = pblk_create_global_caches();
if (!ret)
kref_get(&pblk_caches.kref);
mutex_unlock(&pblk_caches.mutex);
return ret;
}
static void pblk_destroy_global_caches(struct kref *ref)
{
struct pblk_global_caches *c;
c = container_of(ref, struct pblk_global_caches, kref);
kmem_cache_destroy(c->ws);
kmem_cache_destroy(c->rec);
kmem_cache_destroy(c->g_rq);
kmem_cache_destroy(c->w_rq);
}
static void pblk_put_global_caches(void)
{
mutex_lock(&pblk_caches.mutex);
kref_put(&pblk_caches.kref, pblk_destroy_global_caches);
mutex_unlock(&pblk_caches.mutex);
}
static int pblk_core_init(struct pblk *pblk)
@ -382,7 +424,7 @@ static int pblk_core_init(struct pblk *pblk)
if (!pblk->pad_dist)
return -ENOMEM;
if (pblk_init_global_caches(pblk))
if (pblk_get_global_caches())
goto fail_free_pad_dist;
/* Internal bios can be at most the sectors signaled by the device. */
@ -391,27 +433,27 @@ static int pblk_core_init(struct pblk *pblk)
goto free_global_caches;
ret = mempool_init_slab_pool(&pblk->gen_ws_pool, PBLK_GEN_WS_POOL_SIZE,
pblk_ws_cache);
pblk_caches.ws);
if (ret)
goto free_page_bio_pool;
ret = mempool_init_slab_pool(&pblk->rec_pool, geo->all_luns,
pblk_rec_cache);
pblk_caches.rec);
if (ret)
goto free_gen_ws_pool;
ret = mempool_init_slab_pool(&pblk->r_rq_pool, geo->all_luns,
pblk_g_rq_cache);
pblk_caches.g_rq);
if (ret)
goto free_rec_pool;
ret = mempool_init_slab_pool(&pblk->e_rq_pool, geo->all_luns,
pblk_g_rq_cache);
pblk_caches.g_rq);
if (ret)
goto free_r_rq_pool;
ret = mempool_init_slab_pool(&pblk->w_rq_pool, geo->all_luns,
pblk_w_rq_cache);
pblk_caches.w_rq);
if (ret)
goto free_e_rq_pool;
@ -457,7 +499,7 @@ static int pblk_core_init(struct pblk *pblk)
free_page_bio_pool:
mempool_exit(&pblk->page_bio_pool);
free_global_caches:
pblk_free_global_caches(pblk);
pblk_put_global_caches();
fail_free_pad_dist:
kfree(pblk->pad_dist);
return -ENOMEM;
@ -481,7 +523,7 @@ static void pblk_core_free(struct pblk *pblk)
mempool_exit(&pblk->e_rq_pool);
mempool_exit(&pblk->w_rq_pool);
pblk_free_global_caches(pblk);
pblk_put_global_caches();
kfree(pblk->pad_dist);
}
@ -1074,7 +1116,6 @@ static void pblk_exit(void *private, bool graceful)
{
struct pblk *pblk = private;
down_write(&pblk_lock);
pblk_gc_exit(pblk, graceful);
pblk_tear_down(pblk, graceful);
@ -1083,7 +1124,6 @@ static void pblk_exit(void *private, bool graceful)
#endif
pblk_free(pblk);
up_write(&pblk_lock);
}
static sector_t pblk_capacity(void *private)