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Date: Wed, 10 Jun 2015 16:54:24 -0400
From: Dan Streetman <ddstreet@...e.org>
To: Seth Jennings <sjennings@...iantweb.net>,
Andrew Morton <akpm@...ux-foundation.org>
Cc: Linux-MM <linux-mm@...ck.org>,
linux-kernel <linux-kernel@...r.kernel.org>,
Dan Streetman <ddstreet@...e.org>
Subject: Re: [PATCH] zswap: dynamic pool creation
On Thu, Jun 4, 2015 at 8:13 AM, Dan Streetman <ddstreet@...e.org> wrote:
> On Thu, Jun 4, 2015 at 8:02 AM, Dan Streetman <ddstreet@...e.org> wrote:
>> Add dynamic creation of pools. Move the static crypto compression
>> per-cpu transforms into each pool. Add a pointer to zswap_entry to
>> the pool it's in.
>
> Seth, as far as the design, from your previous comments I assume you
> were thinking of maintaining separate lists of zpools and compressors?
> I do see how that will reduce duplication of zpools and compressors,
> but it also requires adding a new pointer to each zswap_entry, and
> increasing the amount of code to manage each list separately. And the
> most common case in zswap will be just a single zpool and compressor,
> not repeatedly changing params. What do you think?
Any opinion on this patch? If you want, I can break it up so there's
a list of zpools and a list of compressors. Either the combined way
(this patch) or separate lists works for me, as long as the params are
changeable at runtime :-)
>
>>
>> This is required by a separate patch which enables changing the
>> zswap zpool and compressor params at runtime.
>>
>> Signed-off-by: Dan Streetman <ddstreet@...e.org>
>> ---
>> mm/zswap.c | 550 +++++++++++++++++++++++++++++++++++++++++++++----------------
>> 1 file changed, 408 insertions(+), 142 deletions(-)
>>
>> diff --git a/mm/zswap.c b/mm/zswap.c
>> index 2d5727b..fc93770 100644
>> --- a/mm/zswap.c
>> +++ b/mm/zswap.c
>> @@ -99,66 +99,19 @@ module_param_named(zpool, zswap_zpool_type, charp, 0444);
>> static struct zpool *zswap_pool;
>>
>> /*********************************
>> -* compression functions
>> +* data structures
>> **********************************/
>> -/* per-cpu compression transforms */
>> -static struct crypto_comp * __percpu *zswap_comp_pcpu_tfms;
>>
>> -enum comp_op {
>> - ZSWAP_COMPOP_COMPRESS,
>> - ZSWAP_COMPOP_DECOMPRESS
>> +struct zswap_pool {
>> + struct zpool *zpool;
>> + struct kref kref;
>> + struct list_head list;
>> + struct rcu_head rcu_head;
>> + struct notifier_block notifier;
>> + char tfm_name[CRYPTO_MAX_ALG_NAME];
>> + struct crypto_comp * __percpu *tfm;
>> };
>>
>> -static int zswap_comp_op(enum comp_op op, const u8 *src, unsigned int slen,
>> - u8 *dst, unsigned int *dlen)
>> -{
>> - struct crypto_comp *tfm;
>> - int ret;
>> -
>> - tfm = *per_cpu_ptr(zswap_comp_pcpu_tfms, get_cpu());
>> - switch (op) {
>> - case ZSWAP_COMPOP_COMPRESS:
>> - ret = crypto_comp_compress(tfm, src, slen, dst, dlen);
>> - break;
>> - case ZSWAP_COMPOP_DECOMPRESS:
>> - ret = crypto_comp_decompress(tfm, src, slen, dst, dlen);
>> - break;
>> - default:
>> - ret = -EINVAL;
>> - }
>> -
>> - put_cpu();
>> - return ret;
>> -}
>> -
>> -static int __init zswap_comp_init(void)
>> -{
>> - if (!crypto_has_comp(zswap_compressor, 0, 0)) {
>> - pr_info("%s compressor not available\n", zswap_compressor);
>> - /* fall back to default compressor */
>> - zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT;
>> - if (!crypto_has_comp(zswap_compressor, 0, 0))
>> - /* can't even load the default compressor */
>> - return -ENODEV;
>> - }
>> - pr_info("using %s compressor\n", zswap_compressor);
>> -
>> - /* alloc percpu transforms */
>> - zswap_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
>> - if (!zswap_comp_pcpu_tfms)
>> - return -ENOMEM;
>> - return 0;
>> -}
>> -
>> -static void __init zswap_comp_exit(void)
>> -{
>> - /* free percpu transforms */
>> - free_percpu(zswap_comp_pcpu_tfms);
>> -}
>> -
>> -/*********************************
>> -* data structures
>> -**********************************/
>> /*
>> * struct zswap_entry
>> *
>> @@ -166,22 +119,24 @@ static void __init zswap_comp_exit(void)
>> * page within zswap.
>> *
>> * rbnode - links the entry into red-black tree for the appropriate swap type
>> + * offset - the swap offset for the entry. Index into the red-black tree.
>> * refcount - the number of outstanding reference to the entry. This is needed
>> * to protect against premature freeing of the entry by code
>> * concurrent calls to load, invalidate, and writeback. The lock
>> * for the zswap_tree structure that contains the entry must
>> * be held while changing the refcount. Since the lock must
>> * be held, there is no reason to also make refcount atomic.
>> - * offset - the swap offset for the entry. Index into the red-black tree.
>> - * handle - zpool allocation handle that stores the compressed page data
>> * length - the length in bytes of the compressed page data. Needed during
>> * decompression
>> + * pool - the zswap_pool the entry's data is in
>> + * handle - zpool allocation handle that stores the compressed page data
>> */
>> struct zswap_entry {
>> struct rb_node rbnode;
>> pgoff_t offset;
>> int refcount;
>> unsigned int length;
>> + struct zswap_pool *pool;
>> unsigned long handle;
>> };
>>
>> @@ -201,6 +156,44 @@ struct zswap_tree {
>>
>> static struct zswap_tree *zswap_trees[MAX_SWAPFILES];
>>
>> +/* RCU-protected iteration */
>> +static LIST_HEAD(zswap_pools);
>> +/* protects zswap_pools list modification */
>> +static DEFINE_SPINLOCK(zswap_pools_lock);
>> +
>> +/*********************************
>> +* helpers and fwd declarations
>> +**********************************/
>> +
>> +#define zswap_pool_debug(msg, p) \
>> + pr_debug("%s pool %s/%s\n", msg, (p)->tfm_name, \
>> + zpool_get_type((p)->zpool))
>> +
>> +static int zswap_writeback_entry(struct zpool *pool, unsigned long handle);
>> +static int zswap_pool_get(struct zswap_pool *pool);
>> +static void zswap_pool_put(struct zswap_pool *pool);
>> +
>> +static bool zswap_is_full(void)
>> +{
>> + return totalram_pages * zswap_max_pool_percent / 100 <
>> + DIV_ROUND_UP(zswap_pool_total_size, PAGE_SIZE);
>> +}
>> +
>> +static void zswap_update_total_size(void)
>> +{
>> + struct zswap_pool *pool;
>> + u64 total = 0;
>> +
>> + rcu_read_lock();
>> +
>> + list_for_each_entry_rcu(pool, &zswap_pools, list)
>> + total += zpool_get_total_size(pool->zpool);
>> +
>> + rcu_read_unlock();
>> +
>> + zswap_pool_total_size = total;
>> +}
>> +
>> /*********************************
>> * zswap entry functions
>> **********************************/
>> @@ -294,10 +287,11 @@ static void zswap_rb_erase(struct rb_root *root, struct zswap_entry *entry)
>> */
>> static void zswap_free_entry(struct zswap_entry *entry)
>> {
>> - zpool_free(zswap_pool, entry->handle);
>> + zpool_free(entry->pool->zpool, entry->handle);
>> + zswap_pool_put(entry->pool);
>> zswap_entry_cache_free(entry);
>> atomic_dec(&zswap_stored_pages);
>> - zswap_pool_total_size = zpool_get_total_size(zswap_pool);
>> + zswap_update_total_size();
>> }
>>
>> /* caller must hold the tree lock */
>> @@ -339,35 +333,21 @@ static struct zswap_entry *zswap_entry_find_get(struct rb_root *root,
>> **********************************/
>> static DEFINE_PER_CPU(u8 *, zswap_dstmem);
>>
>> -static int __zswap_cpu_notifier(unsigned long action, unsigned long cpu)
>> +static int __zswap_cpu_dstmem_notifier(unsigned long action, unsigned long cpu)
>> {
>> - struct crypto_comp *tfm;
>> u8 *dst;
>>
>> switch (action) {
>> case CPU_UP_PREPARE:
>> - tfm = crypto_alloc_comp(zswap_compressor, 0, 0);
>> - if (IS_ERR(tfm)) {
>> - pr_err("can't allocate compressor transform\n");
>> - return NOTIFY_BAD;
>> - }
>> - *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = tfm;
>> dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
>> if (!dst) {
>> pr_err("can't allocate compressor buffer\n");
>> - crypto_free_comp(tfm);
>> - *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = NULL;
>> return NOTIFY_BAD;
>> }
>> per_cpu(zswap_dstmem, cpu) = dst;
>> break;
>> case CPU_DEAD:
>> case CPU_UP_CANCELED:
>> - tfm = *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu);
>> - if (tfm) {
>> - crypto_free_comp(tfm);
>> - *per_cpu_ptr(zswap_comp_pcpu_tfms, cpu) = NULL;
>> - }
>> dst = per_cpu(zswap_dstmem, cpu);
>> kfree(dst);
>> per_cpu(zswap_dstmem, cpu) = NULL;
>> @@ -378,43 +358,309 @@ static int __zswap_cpu_notifier(unsigned long action, unsigned long cpu)
>> return NOTIFY_OK;
>> }
>>
>> -static int zswap_cpu_notifier(struct notifier_block *nb,
>> - unsigned long action, void *pcpu)
>> +static int zswap_cpu_dstmem_notifier(struct notifier_block *nb,
>> + unsigned long action, void *pcpu)
>> {
>> - unsigned long cpu = (unsigned long)pcpu;
>> - return __zswap_cpu_notifier(action, cpu);
>> + return __zswap_cpu_dstmem_notifier(action, (unsigned long)pcpu);
>> }
>>
>> -static struct notifier_block zswap_cpu_notifier_block = {
>> - .notifier_call = zswap_cpu_notifier
>> +static struct notifier_block zswap_dstmem_notifier = {
>> + .notifier_call = zswap_cpu_dstmem_notifier,
>> };
>>
>> -static int __init zswap_cpu_init(void)
>> +static int __init zswap_cpu_dstmem_init(void)
>> {
>> unsigned long cpu;
>>
>> cpu_notifier_register_begin();
>> for_each_online_cpu(cpu)
>> - if (__zswap_cpu_notifier(CPU_UP_PREPARE, cpu) != NOTIFY_OK)
>> + if (__zswap_cpu_dstmem_notifier(CPU_UP_PREPARE, cpu) ==
>> + NOTIFY_BAD)
>> goto cleanup;
>> - __register_cpu_notifier(&zswap_cpu_notifier_block);
>> + __register_cpu_notifier(&zswap_dstmem_notifier);
>> cpu_notifier_register_done();
>> return 0;
>>
>> cleanup:
>> for_each_online_cpu(cpu)
>> - __zswap_cpu_notifier(CPU_UP_CANCELED, cpu);
>> + __zswap_cpu_dstmem_notifier(CPU_UP_CANCELED, cpu);
>> cpu_notifier_register_done();
>> return -ENOMEM;
>> }
>>
>> +static void zswap_cpu_dstmem_destroy(void)
>> +{
>> + unsigned long cpu;
>> +
>> + cpu_notifier_register_begin();
>> + for_each_online_cpu(cpu)
>> + __zswap_cpu_dstmem_notifier(CPU_UP_CANCELED, cpu);
>> + __unregister_cpu_notifier(&zswap_dstmem_notifier);
>> + cpu_notifier_register_done();
>> +}
>> +
>> +static int __zswap_cpu_comp_notifier(struct zswap_pool *pool,
>> + unsigned long action, unsigned long cpu)
>> +{
>> + struct crypto_comp *tfm;
>> +
>> + switch (action) {
>> + case CPU_UP_PREPARE:
>> + if (WARN_ON(*per_cpu_ptr(pool->tfm, cpu)))
>> + break;
>> + tfm = crypto_alloc_comp(pool->tfm_name, 0, 0);
>> + if (IS_ERR_OR_NULL(tfm)) {
>> + pr_err("could not alloc crypto comp %s : %ld\n",
>> + pool->tfm_name, PTR_ERR(tfm));
>> + return NOTIFY_BAD;
>> + }
>> + *per_cpu_ptr(pool->tfm, cpu) = tfm;
>> + break;
>> + case CPU_DEAD:
>> + case CPU_UP_CANCELED:
>> + tfm = *per_cpu_ptr(pool->tfm, cpu);
>> + if (!IS_ERR_OR_NULL(tfm))
>> + crypto_free_comp(tfm);
>> + *per_cpu_ptr(pool->tfm, cpu) = NULL;
>> + break;
>> + default:
>> + break;
>> + }
>> + return NOTIFY_OK;
>> +}
>> +
>> +static int zswap_cpu_comp_notifier(struct notifier_block *nb,
>> + unsigned long action, void *pcpu)
>> +{
>> + unsigned long cpu = (unsigned long)pcpu;
>> + struct zswap_pool *pool = container_of(nb, typeof(*pool), notifier);
>> +
>> + return __zswap_cpu_comp_notifier(pool, action, cpu);
>> +}
>> +
>> +static int zswap_cpu_comp_init(struct zswap_pool *pool)
>> +{
>> + unsigned long cpu;
>> +
>> + memset(&pool->notifier, 0, sizeof(pool->notifier));
>> + pool->notifier.notifier_call = zswap_cpu_comp_notifier;
>> +
>> + cpu_notifier_register_begin();
>> + for_each_online_cpu(cpu)
>> + if (__zswap_cpu_comp_notifier(pool, CPU_UP_PREPARE, cpu) ==
>> + NOTIFY_BAD)
>> + goto cleanup;
>> + __register_cpu_notifier(&pool->notifier);
>> + cpu_notifier_register_done();
>> + return 0;
>> +
>> +cleanup:
>> + for_each_online_cpu(cpu)
>> + __zswap_cpu_comp_notifier(pool, CPU_UP_CANCELED, cpu);
>> + cpu_notifier_register_done();
>> + return -ENOMEM;
>> +}
>> +
>> +static void zswap_cpu_comp_destroy(struct zswap_pool *pool)
>> +{
>> + unsigned long cpu;
>> +
>> + cpu_notifier_register_begin();
>> + for_each_online_cpu(cpu)
>> + __zswap_cpu_comp_notifier(pool, CPU_UP_CANCELED, cpu);
>> + __unregister_cpu_notifier(&pool->notifier);
>> + cpu_notifier_register_done();
>> +}
>> +
>> /*********************************
>> -* helpers
>> +* pool functions
>> **********************************/
>> -static bool zswap_is_full(void)
>> +
>> +static struct zswap_pool *__zswap_pool_current(void)
>> {
>> - return totalram_pages * zswap_max_pool_percent / 100 <
>> - DIV_ROUND_UP(zswap_pool_total_size, PAGE_SIZE);
>> + struct zswap_pool *pool;
>> +
>> + pool = list_first_or_null_rcu(&zswap_pools, typeof(*pool), list);
>> + WARN_ON(!pool);
>> +
>> + return pool;
>> +}
>> +
>> +static struct zswap_pool *zswap_pool_current(void)
>> +{
>> + assert_spin_locked(&zswap_pools_lock);
>> +
>> + return __zswap_pool_current();
>> +}
>> +
>> +static struct zswap_pool *zswap_pool_current_get(void)
>> +{
>> + struct zswap_pool *pool;
>> +
>> + rcu_read_lock();
>> +
>> + pool = __zswap_pool_current();
>> + if (!pool || !zswap_pool_get(pool))
>> + pool = NULL;
>> +
>> + rcu_read_unlock();
>> +
>> + return pool;
>> +}
>> +
>> +static struct zswap_pool *zswap_pool_last_get(void)
>> +{
>> + struct zswap_pool *pool, *last = NULL;
>> +
>> + rcu_read_lock();
>> +
>> + list_for_each_entry_rcu(pool, &zswap_pools, list)
>> + last = pool;
>> + if (!WARN_ON(!last) && !zswap_pool_get(last))
>> + last = NULL;
>> +
>> + rcu_read_unlock();
>> +
>> + return last;
>> +}
>> +
>> +static struct zpool_ops zswap_zpool_ops = {
>> + .evict = zswap_writeback_entry
>> +};
>> +
>> +static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
>> +{
>> + struct zswap_pool *pool;
>> +
>> + assert_spin_locked(&zswap_pools_lock);
>> +
>> + list_for_each_entry_rcu(pool, &zswap_pools, list) {
>> + if (strncmp(pool->tfm_name, compressor, sizeof(pool->tfm_name)))
>> + continue;
>> + if (strncmp(zpool_get_type(pool->zpool), type,
>> + sizeof(zswap_zpool_type)))
>> + continue;
>> + /* if we can't get it, it's about to be destroyed */
>> + if (!zswap_pool_get(pool))
>> + continue;
>> + return pool;
>> + }
>> +
>> + return NULL;
>> +}
>> +
>> +static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
>> +{
>> + struct zswap_pool *pool;
>> + gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN;
>> +
>> + pool = kzalloc(sizeof(*pool), GFP_KERNEL);
>> + if (!pool) {
>> + pr_err("pool alloc failed\n");
>> + return NULL;
>> + }
>> +
>> + pool->zpool = zpool_create_pool(type, "zswap", gfp, &zswap_zpool_ops);
>> + if (!pool->zpool) {
>> + pr_err("%s zpool not available\n", type);
>> + goto error;
>> + }
>> + 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) {
>> + pr_err("percpu alloc failed\n");
>> + goto error;
>> + }
>> +
>> + if (zswap_cpu_comp_init(pool))
>> + goto error;
>> + pr_debug("using %s compressor\n", pool->tfm_name);
>> +
>> + /* being the current pool takes 1 ref; this func expects the
>> + * caller to always add the new pool as the current pool
>> + */
>> + kref_init(&pool->kref);
>> + INIT_LIST_HEAD(&pool->list);
>> +
>> + zswap_pool_debug("created", pool);
>> +
>> + return pool;
>> +
>> +error:
>> + free_percpu(pool->tfm);
>> + if (pool->zpool)
>> + zpool_destroy_pool(pool->zpool);
>> + kfree(pool);
>> + return NULL;
>> +}
>> +
>> +static struct zswap_pool *__zswap_pool_create_fallback(void)
>> +{
>> + if (!crypto_has_comp(zswap_compressor, 0, 0)) {
>> + pr_err("compressor %s not available, using default %s\n",
>> + zswap_compressor, ZSWAP_COMPRESSOR_DEFAULT);
>> + strncpy(zswap_compressor, ZSWAP_COMPRESSOR_DEFAULT,
>> + sizeof(zswap_compressor));
>> + }
>> + if (!zpool_has_pool(zswap_zpool_type)) {
>> + pr_err("zpool %s not available, using default %s\n",
>> + zswap_zpool_type, ZSWAP_ZPOOL_DEFAULT);
>> + strncpy(zswap_zpool_type, ZSWAP_ZPOOL_DEFAULT,
>> + sizeof(zswap_zpool_type));
>> + }
>> +
>> + return zswap_pool_create(zswap_zpool_type, zswap_compressor);
>> +}
>> +
>> +static void zswap_pool_destroy(struct zswap_pool *pool)
>> +{
>> + zswap_pool_debug("destroying", pool);
>> +
>> + zswap_cpu_comp_destroy(pool);
>> + free_percpu(pool->tfm);
>> + zpool_destroy_pool(pool->zpool);
>> + kfree(pool);
>> +}
>> +
>> +static int __must_check zswap_pool_get(struct zswap_pool *pool)
>> +{
>> + return kref_get_unless_zero(&pool->kref);
>> +}
>> +
>> +static void __zswap_pool_release(struct rcu_head *head)
>> +{
>> + struct zswap_pool *pool = container_of(head, typeof(*pool), rcu_head);
>> +
>> + /* nobody should have been able to get a kref... */
>> + WARN_ON(kref_get_unless_zero(&pool->kref));
>> +
>> + /* pool is now off zswap_pools list and has no references. */
>> + zswap_pool_destroy(pool);
>> +}
>> +
>> +static void __zswap_pool_empty(struct kref *kref)
>> +{
>> + struct zswap_pool *pool;
>> +
>> + pool = container_of(kref, typeof(*pool), kref);
>> +
>> + spin_lock(&zswap_pools_lock);
>> +
>> + WARN_ON(pool == zswap_pool_current());
>> +
>> + list_del_rcu(&pool->list);
>> + call_rcu(&pool->rcu_head, __zswap_pool_release);
>> +
>> + spin_unlock(&zswap_pools_lock);
>> +}
>> +
>> +static void zswap_pool_put(struct zswap_pool *pool)
>> +{
>> + kref_put(&pool->kref, __zswap_pool_empty);
>> +}
>> +
>> }
>>
>> /*********************************
>> @@ -538,6 +784,7 @@ 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;
>> unsigned int dlen;
>> int ret;
>> @@ -578,13 +825,15 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
>> case ZSWAP_SWAPCACHE_NEW: /* page is locked */
>> /* decompress */
>> dlen = PAGE_SIZE;
>> - src = (u8 *)zpool_map_handle(zswap_pool, entry->handle,
>> + src = (u8 *)zpool_map_handle(entry->pool->zpool, entry->handle,
>> ZPOOL_MM_RO) + sizeof(struct zswap_header);
>> dst = kmap_atomic(page);
>> - ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src,
>> - entry->length, dst, &dlen);
>> + 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);
>> - zpool_unmap_handle(zswap_pool, entry->handle);
>> + zpool_unmap_handle(entry->pool->zpool, entry->handle);
>> BUG_ON(ret);
>> BUG_ON(dlen != PAGE_SIZE);
>>
>> @@ -633,6 +882,22 @@ end:
>> return ret;
>> }
>>
>> +static int zswap_shrink(void)
>> +{
>> + struct zswap_pool *pool;
>> + int ret;
>> +
>> + pool = zswap_pool_last_get();
>> + if (!pool)
>> + return -ENOENT;
>> +
>> + ret = zpool_shrink(pool->zpool, 1, NULL);
>> +
>> + zswap_pool_put(pool);
>> +
>> + return ret;
>> +}
>> +
>> /*********************************
>> * frontswap hooks
>> **********************************/
>> @@ -642,6 +907,7 @@ 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;
>> int ret;
>> unsigned int dlen = PAGE_SIZE, len;
>> unsigned long handle;
>> @@ -657,7 +923,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
>> /* reclaim space if needed */
>> if (zswap_is_full()) {
>> zswap_pool_limit_hit++;
>> - if (zpool_shrink(zswap_pool, 1, NULL)) {
>> + if (zswap_shrink()) {
>> zswap_reject_reclaim_fail++;
>> ret = -ENOMEM;
>> goto reject;
>> @@ -672,33 +938,42 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
>> goto reject;
>> }
>>
>> + /* if entry is successfully added, it keeps the reference */
>> + entry->pool = zswap_pool_current_get();
>> + if (!entry->pool) {
>> + ret = -EINVAL;
>> + goto freepage;
>> + }
>> +
>> /* compress */
>> dst = get_cpu_var(zswap_dstmem);
>> + tfm = *get_cpu_ptr(entry->pool->tfm);
>> src = kmap_atomic(page);
>> - ret = zswap_comp_op(ZSWAP_COMPOP_COMPRESS, src, PAGE_SIZE, dst, &dlen);
>> + ret = crypto_comp_compress(tfm, src, PAGE_SIZE, dst, &dlen);
>> kunmap_atomic(src);
>> + put_cpu_ptr(entry->pool->tfm);
>> if (ret) {
>> ret = -EINVAL;
>> - goto freepage;
>> + goto put_dstmem;
>> }
>>
>> /* store */
>> len = dlen + sizeof(struct zswap_header);
>> - ret = zpool_malloc(zswap_pool, len, __GFP_NORETRY | __GFP_NOWARN,
>> - &handle);
>> + ret = zpool_malloc(entry->pool->zpool, len,
>> + __GFP_NORETRY | __GFP_NOWARN, &handle);
>> if (ret == -ENOSPC) {
>> zswap_reject_compress_poor++;
>> - goto freepage;
>> + goto put_dstmem;
>> }
>> if (ret) {
>> zswap_reject_alloc_fail++;
>> - goto freepage;
>> + goto put_dstmem;
>> }
>> - zhdr = zpool_map_handle(zswap_pool, handle, ZPOOL_MM_RW);
>> + zhdr = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_RW);
>> zhdr->swpentry = swp_entry(type, offset);
>> buf = (u8 *)(zhdr + 1);
>> memcpy(buf, dst, dlen);
>> - zpool_unmap_handle(zswap_pool, handle);
>> + zpool_unmap_handle(entry->pool->zpool, handle);
>> put_cpu_var(zswap_dstmem);
>>
>> /* populate entry */
>> @@ -721,12 +996,14 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
>>
>> /* update stats */
>> atomic_inc(&zswap_stored_pages);
>> - zswap_pool_total_size = zpool_get_total_size(zswap_pool);
>> + zswap_update_total_size();
>>
>> return 0;
>>
>> -freepage:
>> +put_dstmem:
>> put_cpu_var(zswap_dstmem);
>> + zswap_pool_put(entry->pool);
>> +freepage:
>> zswap_entry_cache_free(entry);
>> reject:
>> return ret;
>> @@ -741,6 +1018,7 @@ 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;
>> u8 *src, *dst;
>> unsigned int dlen;
>> int ret;
>> @@ -757,13 +1035,14 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset,
>>
>> /* decompress */
>> dlen = PAGE_SIZE;
>> - src = (u8 *)zpool_map_handle(zswap_pool, entry->handle,
>> + src = (u8 *)zpool_map_handle(entry->pool->zpool, entry->handle,
>> ZPOOL_MM_RO) + sizeof(struct zswap_header);
>> dst = kmap_atomic(page);
>> - ret = zswap_comp_op(ZSWAP_COMPOP_DECOMPRESS, src, entry->length,
>> - dst, &dlen);
>> + 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);
>> - zpool_unmap_handle(zswap_pool, entry->handle);
>> + zpool_unmap_handle(entry->pool->zpool, entry->handle);
>> BUG_ON(ret);
>>
>> spin_lock(&tree->lock);
>> @@ -816,10 +1095,6 @@ static void zswap_frontswap_invalidate_area(unsigned type)
>> zswap_trees[type] = NULL;
>> }
>>
>> -static struct zpool_ops zswap_zpool_ops = {
>> - .evict = zswap_writeback_entry
>> -};
>> -
>> static void zswap_frontswap_init(unsigned type)
>> {
>> struct zswap_tree *tree;
>> @@ -900,49 +1175,40 @@ static void __exit zswap_debugfs_exit(void) { }
>> **********************************/
>> static int __init init_zswap(void)
>> {
>> - gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN;
>> + struct zswap_pool *pool;
>>
>> - pr_info("loading zswap\n");
>> -
>> - zswap_pool = zpool_create_pool(zswap_zpool_type, "zswap", gfp,
>> - &zswap_zpool_ops);
>> - if (!zswap_pool && strcmp(zswap_zpool_type, ZSWAP_ZPOOL_DEFAULT)) {
>> - pr_info("%s zpool not available\n", zswap_zpool_type);
>> - zswap_zpool_type = ZSWAP_ZPOOL_DEFAULT;
>> - zswap_pool = zpool_create_pool(zswap_zpool_type, "zswap", gfp,
>> - &zswap_zpool_ops);
>> - }
>> - if (!zswap_pool) {
>> - pr_err("%s zpool not available\n", zswap_zpool_type);
>> - pr_err("zpool creation failed\n");
>> - goto error;
>> - }
>> - pr_info("using %s pool\n", zswap_zpool_type);
>> + pr_info("loading\n");
>>
>> if (zswap_entry_cache_create()) {
>> pr_err("entry cache creation failed\n");
>> - goto cachefail;
>> + goto cache_fail;
>> }
>> - if (zswap_comp_init()) {
>> - pr_err("compressor initialization failed\n");
>> - goto compfail;
>> +
>> + if (zswap_cpu_dstmem_init()) {
>> + pr_err("dstmem alloc failed\n");
>> + goto dstmem_fail;
>> }
>> - if (zswap_cpu_init()) {
>> - pr_err("per-cpu initialization failed\n");
>> - goto pcpufail;
>> +
>> + pool = __zswap_pool_create_fallback();
>> + if (!pool) {
>> + pr_err("pool creation failed\n");
>> + goto pool_fail;
>> }
>> + pr_info("loaded using pool %s/%s\n", pool->tfm_name,
>> + zpool_get_type(pool->zpool));
>> +
>> + list_add(&pool->list, &zswap_pools);
>>
>> frontswap_register_ops(&zswap_frontswap_ops);
>> if (zswap_debugfs_init())
>> pr_warn("debugfs initialization failed\n");
>> return 0;
>> -pcpufail:
>> - zswap_comp_exit();
>> -compfail:
>> +
>> +pool_fail:
>> + zswap_cpu_dstmem_destroy();
>> +dstmem_fail:
>> zswap_entry_cache_destroy();
>> -cachefail:
>> - zpool_destroy_pool(zswap_pool);
>> -error:
>> +cache_fail:
>> return -ENOMEM;
>> }
>> /* must be late so crypto has time to come up */
>> --
>> 2.1.0
>>
--
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