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-rw-r--r--mm/zswap.c183
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);