diff options
Diffstat (limited to 'mm/zswap.c')
| -rw-r--r-- | mm/zswap.c | 183 |
1 files changed, 137 insertions, 46 deletions
diff --git a/mm/zswap.c b/mm/zswap.c index 55a2f72557a8..182f6ad5aa69 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -24,8 +24,10 @@ #include <linux/rbtree.h> #include <linux/swap.h> #include <linux/crypto.h> +#include <linux/scatterlist.h> #include <linux/mempool.h> #include <linux/zpool.h> +#include <crypto/acompress.h> #include <linux/mm_types.h> #include <linux/page-flags.h> @@ -127,9 +129,17 @@ module_param_named(same_filled_pages_enabled, zswap_same_filled_pages_enabled, * data structures **********************************/ +struct crypto_acomp_ctx { + struct crypto_acomp *acomp; + struct acomp_req *req; + struct crypto_wait wait; + u8 *dstmem; + struct mutex *mutex; +}; + struct zswap_pool { struct zpool *zpool; - struct crypto_comp * __percpu *tfm; + struct crypto_acomp_ctx __percpu *acomp_ctx; struct kref kref; struct list_head list; struct work_struct release_work; @@ -388,23 +398,43 @@ static struct zswap_entry *zswap_entry_find_get(struct rb_root *root, * per-cpu code **********************************/ static DEFINE_PER_CPU(u8 *, zswap_dstmem); +/* + * If users dynamically change the zpool type and compressor at runtime, i.e. + * zswap is running, zswap can have more than one zpool on one cpu, but they + * are sharing dtsmem. So we need this mutex to be per-cpu. + */ +static DEFINE_PER_CPU(struct mutex *, zswap_mutex); static int zswap_dstmem_prepare(unsigned int cpu) { + struct mutex *mutex; u8 *dst; dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu)); if (!dst) return -ENOMEM; + mutex = kmalloc_node(sizeof(*mutex), GFP_KERNEL, cpu_to_node(cpu)); + if (!mutex) { + kfree(dst); + return -ENOMEM; + } + + mutex_init(mutex); per_cpu(zswap_dstmem, cpu) = dst; + per_cpu(zswap_mutex, cpu) = mutex; return 0; } static int zswap_dstmem_dead(unsigned int cpu) { + struct mutex *mutex; u8 *dst; + mutex = per_cpu(zswap_mutex, cpu); + kfree(mutex); + per_cpu(zswap_mutex, cpu) = NULL; + dst = per_cpu(zswap_dstmem, cpu); kfree(dst); per_cpu(zswap_dstmem, cpu) = NULL; @@ -415,30 +445,54 @@ static int zswap_dstmem_dead(unsigned int cpu) static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node) { struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node); - struct crypto_comp *tfm; - - if (WARN_ON(*per_cpu_ptr(pool->tfm, cpu))) - return 0; + struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu); + struct crypto_acomp *acomp; + struct acomp_req *req; + + acomp = crypto_alloc_acomp_node(pool->tfm_name, 0, 0, cpu_to_node(cpu)); + if (IS_ERR(acomp)) { + pr_err("could not alloc crypto acomp %s : %ld\n", + pool->tfm_name, PTR_ERR(acomp)); + return PTR_ERR(acomp); + } + acomp_ctx->acomp = acomp; - tfm = crypto_alloc_comp(pool->tfm_name, 0, 0); - if (IS_ERR(tfm)) { - pr_err("could not alloc crypto comp %s : %ld\n", - pool->tfm_name, PTR_ERR(tfm)); + req = acomp_request_alloc(acomp_ctx->acomp); + if (!req) { + pr_err("could not alloc crypto acomp_request %s\n", + pool->tfm_name); + crypto_free_acomp(acomp_ctx->acomp); return -ENOMEM; } - *per_cpu_ptr(pool->tfm, cpu) = tfm; + acomp_ctx->req = req; + + crypto_init_wait(&acomp_ctx->wait); + /* + * if the backend of acomp is async zip, crypto_req_done() will wakeup + * crypto_wait_req(); if the backend of acomp is scomp, the callback + * won't be called, crypto_wait_req() will return without blocking. + */ + acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + crypto_req_done, &acomp_ctx->wait); + + acomp_ctx->mutex = per_cpu(zswap_mutex, cpu); + acomp_ctx->dstmem = per_cpu(zswap_dstmem, cpu); + return 0; } static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) { struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node); - struct crypto_comp *tfm; + struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu); + + if (!IS_ERR_OR_NULL(acomp_ctx)) { + if (!IS_ERR_OR_NULL(acomp_ctx->req)) + acomp_request_free(acomp_ctx->req); + if (!IS_ERR_OR_NULL(acomp_ctx->acomp)) + crypto_free_acomp(acomp_ctx->acomp); + } - tfm = *per_cpu_ptr(pool->tfm, cpu); - if (!IS_ERR_OR_NULL(tfm)) - crypto_free_comp(tfm); - *per_cpu_ptr(pool->tfm, cpu) = NULL; return 0; } @@ -561,8 +615,9 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor) pr_debug("using %s zpool\n", zpool_get_type(pool->zpool)); strlcpy(pool->tfm_name, compressor, sizeof(pool->tfm_name)); - pool->tfm = alloc_percpu(struct crypto_comp *); - if (!pool->tfm) { + + pool->acomp_ctx = alloc_percpu(*pool->acomp_ctx); + if (!pool->acomp_ctx) { pr_err("percpu alloc failed\n"); goto error; } @@ -585,7 +640,8 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor) return pool; error: - free_percpu(pool->tfm); + if (pool->acomp_ctx) + free_percpu(pool->acomp_ctx); if (pool->zpool) zpool_destroy_pool(pool->zpool); kfree(pool); @@ -596,14 +652,14 @@ static __init struct zswap_pool *__zswap_pool_create_fallback(void) { bool has_comp, has_zpool; - has_comp = crypto_has_comp(zswap_compressor, 0, 0); + has_comp = crypto_has_acomp(zswap_compressor, 0, 0); if (!has_comp && strcmp(zswap_compressor, CONFIG_ZSWAP_COMPRESSOR_DEFAULT)) { pr_err("compressor %s not available, using default %s\n", zswap_compressor, CONFIG_ZSWAP_COMPRESSOR_DEFAULT); param_free_charp(&zswap_compressor); zswap_compressor = CONFIG_ZSWAP_COMPRESSOR_DEFAULT; - has_comp = crypto_has_comp(zswap_compressor, 0, 0); + has_comp = crypto_has_acomp(zswap_compressor, 0, 0); } if (!has_comp) { pr_err("default compressor %s not available\n", @@ -639,7 +695,7 @@ static void zswap_pool_destroy(struct zswap_pool *pool) zswap_pool_debug("destroying", pool); cpuhp_state_remove_instance(CPUHP_MM_ZSWP_POOL_PREPARE, &pool->node); - free_percpu(pool->tfm); + free_percpu(pool->acomp_ctx); zpool_destroy_pool(pool->zpool); kfree(pool); } @@ -723,7 +779,7 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, } type = s; } else if (!compressor) { - if (!crypto_has_comp(s, 0, 0)) { + if (!crypto_has_acomp(s, 0, 0)) { pr_err("compressor %s not available\n", s); return -ENOENT; } @@ -774,7 +830,7 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, * failed, maybe both compressor and zpool params were bad. * Allow changing this param, so pool creation will succeed * when the other param is changed. We already verified this - * param is ok in the zpool_has_pool() or crypto_has_comp() + * param is ok in the zpool_has_pool() or crypto_has_acomp() * checks above. */ ret = param_set_charp(s, kp); @@ -876,8 +932,10 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle) pgoff_t offset; struct zswap_entry *entry; struct page *page; - struct crypto_comp *tfm; - u8 *src, *dst; + struct scatterlist input, output; + struct crypto_acomp_ctx *acomp_ctx; + + u8 *src; unsigned int dlen; int ret; struct writeback_control wbc = { @@ -916,14 +974,20 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle) case ZSWAP_SWAPCACHE_NEW: /* page is locked */ /* decompress */ + acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); + dlen = PAGE_SIZE; src = (u8 *)zhdr + sizeof(struct zswap_header); - dst = kmap_atomic(page); - tfm = *get_cpu_ptr(entry->pool->tfm); - ret = crypto_comp_decompress(tfm, src, entry->length, - dst, &dlen); - put_cpu_ptr(entry->pool->tfm); - kunmap_atomic(dst); + + mutex_lock(acomp_ctx->mutex); + sg_init_one(&input, src, entry->length); + sg_init_table(&output, 1); + sg_set_page(&output, page, PAGE_SIZE, 0); + acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen); + ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait); + dlen = acomp_ctx->req->dlen; + mutex_unlock(acomp_ctx->mutex); + BUG_ON(ret); BUG_ON(dlen != PAGE_SIZE); @@ -1004,7 +1068,8 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, { struct zswap_tree *tree = zswap_trees[type]; struct zswap_entry *entry, *dupentry; - struct crypto_comp *tfm; + struct scatterlist input, output; + struct crypto_acomp_ctx *acomp_ctx; int ret; unsigned int hlen, dlen = PAGE_SIZE; unsigned long handle, value; @@ -1074,12 +1139,32 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, } /* compress */ - dst = get_cpu_var(zswap_dstmem); - tfm = *get_cpu_ptr(entry->pool->tfm); - src = kmap_atomic(page); - ret = crypto_comp_compress(tfm, src, PAGE_SIZE, dst, &dlen); - kunmap_atomic(src); - put_cpu_ptr(entry->pool->tfm); + acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); + + mutex_lock(acomp_ctx->mutex); + + dst = acomp_ctx->dstmem; + sg_init_table(&input, 1); + sg_set_page(&input, page, PAGE_SIZE, 0); + + /* zswap_dstmem is of size (PAGE_SIZE * 2). Reflect same in sg_list */ + sg_init_one(&output, dst, PAGE_SIZE * 2); + acomp_request_set_params(acomp_ctx->req, &input, &output, PAGE_SIZE, dlen); + /* + * it maybe looks a little bit silly that we send an asynchronous request, + * then wait for its completion synchronously. This makes the process look + * synchronous in fact. + * Theoretically, acomp supports users send multiple acomp requests in one + * acomp instance, then get those requests done simultaneously. but in this + * case, frontswap actually does store and load page by page, there is no + * existing method to send the second page before the first page is done + * in one thread doing frontswap. + * but in different threads running on different cpu, we have different + * acomp instance, so multiple threads can do (de)compression in parallel. + */ + ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait); + dlen = acomp_ctx->req->dlen; + if (ret) { ret = -EINVAL; goto put_dstmem; @@ -1103,7 +1188,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, memcpy(buf, &zhdr, hlen); memcpy(buf + hlen, dst, dlen); zpool_unmap_handle(entry->pool->zpool, handle); - put_cpu_var(zswap_dstmem); + mutex_unlock(acomp_ctx->mutex); /* populate entry */ entry->offset = offset; @@ -1131,7 +1216,7 @@ insert_entry: return 0; put_dstmem: - put_cpu_var(zswap_dstmem); + mutex_unlock(acomp_ctx->mutex); zswap_pool_put(entry->pool); freepage: zswap_entry_cache_free(entry); @@ -1148,7 +1233,8 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset, { struct zswap_tree *tree = zswap_trees[type]; struct zswap_entry *entry; - struct crypto_comp *tfm; + struct scatterlist input, output; + struct crypto_acomp_ctx *acomp_ctx; u8 *src, *dst; unsigned int dlen; int ret; @@ -1175,11 +1261,16 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset, src = zpool_map_handle(entry->pool->zpool, entry->handle, ZPOOL_MM_RO); if (zpool_evictable(entry->pool->zpool)) src += sizeof(struct zswap_header); - dst = kmap_atomic(page); - tfm = *get_cpu_ptr(entry->pool->tfm); - ret = crypto_comp_decompress(tfm, src, entry->length, dst, &dlen); - put_cpu_ptr(entry->pool->tfm); - kunmap_atomic(dst); + + acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); + mutex_lock(acomp_ctx->mutex); + sg_init_one(&input, src, entry->length); + sg_init_table(&output, 1); + sg_set_page(&output, page, PAGE_SIZE, 0); + acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, dlen); + ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait); + mutex_unlock(acomp_ctx->mutex); + zpool_unmap_handle(entry->pool->zpool, entry->handle); BUG_ON(ret); |