This patch does the following:
1) Defines ZSWAP_MAX_BATCH_SIZE to denote the maximum number of acomp_ctx
batching resources (acomp_reqs and buffers) to allocate if the zswap
compressor supports batching. Currently, ZSWAP_MAX_BATCH_SIZE is set to
8U.
2) Modifies the definition of "struct crypto_acomp_ctx" to represent a
configurable number of acomp_reqs and buffers. Adds a "nr_reqs" to
"struct crypto_acomp_ctx" to contain the number of resources that will
be allocated in the cpu hotplug onlining code.
3) The zswap_cpu_comp_prepare() cpu onlining code will detect if the
crypto_acomp created for the zswap pool (in other words, the zswap
compression algorithm) has registered implementations for
batch_compress() and batch_decompress(). If so, it will query the
crypto_acomp for the maximum batch size supported by the compressor, and
set "nr_reqs" to the minimum of this compressor-specific max batch size
and ZSWAP_MAX_BATCH_SIZE. Finally, it will allocate "nr_reqs"
reqs/buffers, and set the acomp_ctx->nr_reqs accordingly.
4) If the crypto_acomp does not support batching, "nr_reqs" defaults to 1.
Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@xxxxxxxxx>
---
mm/zswap.c | 122 +++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 90 insertions(+), 32 deletions(-)
diff --git a/mm/zswap.c b/mm/zswap.c
index 9718c33f8192..99cd78891fd0 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -78,6 +78,13 @@ static bool zswap_pool_reached_full;
#define ZSWAP_PARAM_UNSET ""
+/*
+ * For compression batching of large folios:
+ * Maximum number of acomp compress requests that will be processed
+ * in a batch, iff the zswap compressor supports batching.
+ */
+#define ZSWAP_MAX_BATCH_SIZE 8U
+
static int zswap_setup(void);
/* Enable/disable zswap */
@@ -143,9 +150,10 @@ bool zswap_never_enabled(void)
struct crypto_acomp_ctx {
struct crypto_acomp *acomp;
- struct acomp_req *req;
+ struct acomp_req **reqs;
+ u8 **buffers;
+ unsigned int nr_reqs;
struct crypto_wait wait;
- u8 *buffer;
struct mutex mutex;
bool is_sleepable;
};
@@ -818,49 +826,88 @@ 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_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu);
struct crypto_acomp *acomp;
- struct acomp_req *req;
- int ret;
+ unsigned int nr_reqs = 1;
+ int ret = -ENOMEM;
+ int i, j;
mutex_init(&acomp_ctx->mutex);
-
- acomp_ctx->buffer = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
- if (!acomp_ctx->buffer)
- return -ENOMEM;
+ acomp_ctx->nr_reqs = 0;
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));
- ret = PTR_ERR(acomp);
- goto acomp_fail;
+ return PTR_ERR(acomp);
}
acomp_ctx->acomp = acomp;
acomp_ctx->is_sleepable = acomp_is_async(acomp);
- req = acomp_request_alloc(acomp_ctx->acomp);
- if (!req) {
- pr_err("could not alloc crypto acomp_request %s\n",
- pool->tfm_name);
- ret = -ENOMEM;
+ /*
+ * Create the necessary batching resources if the crypto acomp alg
+ * implements the batch_compress and batch_decompress API.
+ */
+ if (acomp_has_async_batching(acomp)) {
+ nr_reqs = min(ZSWAP_MAX_BATCH_SIZE, crypto_acomp_batch_size(acomp));
+ pr_info_once("Creating acomp_ctx with %d reqs/buffers for batching since crypto acomp\n%s has registered batch_compress() and batch_decompress().\n",
+ nr_reqs, pool->tfm_name);
+ }
+
+ acomp_ctx->buffers = kmalloc_node(nr_reqs * sizeof(u8 *), GFP_KERNEL, cpu_to_node(cpu));
+ if (!acomp_ctx->buffers)
+ goto buf_fail;
+
+ for (i = 0; i < nr_reqs; ++i) {
+ acomp_ctx->buffers[i] = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
+ if (!acomp_ctx->buffers[i]) {
+ for (j = 0; j < i; ++j)
+ kfree(acomp_ctx->buffers[j]);
+ kfree(acomp_ctx->buffers);
+ ret = -ENOMEM;
+ goto buf_fail;
+ }
+ }
+
+ acomp_ctx->reqs = kmalloc_node(nr_reqs * sizeof(struct acomp_req *), GFP_KERNEL, cpu_to_node(cpu));
+ if (!acomp_ctx->reqs)
goto req_fail;
+
+ for (i = 0; i < nr_reqs; ++i) {
+ acomp_ctx->reqs[i] = acomp_request_alloc(acomp_ctx->acomp);
+ if (!acomp_ctx->reqs[i]) {
+ pr_err("could not alloc crypto acomp_request reqs[%d] %s\n",
+ i, pool->tfm_name);
+ for (j = 0; j < i; ++j)
+ acomp_request_free(acomp_ctx->reqs[j]);
+ kfree(acomp_ctx->reqs);
+ ret = -ENOMEM;
+ goto req_fail;
+ }
}
- acomp_ctx->req = req;
+ /*
+ * The crypto_wait is used only in fully synchronous, i.e., with scomp
+ * or non-poll mode of acomp, hence there is only one "wait" per
+ * acomp_ctx, with callback set to reqs[0], under the assumption that
+ * there is at least 1 request per acomp_ctx.
+ */
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,
+ acomp_request_set_callback(acomp_ctx->reqs[0], CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &acomp_ctx->wait);
+ acomp_ctx->nr_reqs = nr_reqs;
return 0;
req_fail:
+ for (i = 0; i < nr_reqs; ++i)
+ kfree(acomp_ctx->buffers[i]);
+ kfree(acomp_ctx->buffers);
+buf_fail:
crypto_free_acomp(acomp_ctx->acomp);
-acomp_fail:
- kfree(acomp_ctx->buffer);
return ret;
}
@@ -870,11 +917,22 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node)
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);
+ int i;
+
+ for (i = 0; i < acomp_ctx->nr_reqs; ++i)
+ if (!IS_ERR_OR_NULL(acomp_ctx->reqs[i]))
+ acomp_request_free(acomp_ctx->reqs[i]);
+ kfree(acomp_ctx->reqs);
+
+ for (i = 0; i < acomp_ctx->nr_reqs; ++i)
+ kfree(acomp_ctx->buffers[i]);
+ kfree(acomp_ctx->buffers);
+
if (!IS_ERR_OR_NULL(acomp_ctx->acomp))
crypto_free_acomp(acomp_ctx->acomp);
- kfree(acomp_ctx->buffer);
+
+ acomp_ctx->nr_reqs = 0;
+ acomp_ctx = NULL;
}
return 0;
@@ -897,7 +955,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
mutex_lock(&acomp_ctx->mutex);
- dst = acomp_ctx->buffer;
+ dst = acomp_ctx->buffers[0];
sg_init_table(&input, 1);
sg_set_page(&input, page, PAGE_SIZE, 0);
@@ -907,7 +965,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
* giving the dst buffer with enough length to avoid buffer overflow.
*/
sg_init_one(&output, dst, PAGE_SIZE * 2);
- acomp_request_set_params(acomp_ctx->req, &input, &output, PAGE_SIZE, dlen);
+ acomp_request_set_params(acomp_ctx->reqs[0], &input, &output, PAGE_SIZE, dlen);
/*
* it maybe looks a little bit silly that we send an asynchronous request,
@@ -921,8 +979,8 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
* but in different threads running on different cpu, we have different
* acomp instance, so multiple threads can do (de)compression in parallel.
*/
- comp_ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait);
- dlen = acomp_ctx->req->dlen;
+ comp_ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->reqs[0]), &acomp_ctx->wait);
+ dlen = acomp_ctx->reqs[0]->dlen;
if (comp_ret)
goto unlock;
@@ -975,20 +1033,20 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio)
*/
if ((acomp_ctx->is_sleepable && !zpool_can_sleep_mapped(zpool)) ||
!virt_addr_valid(src)) {
- memcpy(acomp_ctx->buffer, src, entry->length);
- src = acomp_ctx->buffer;
+ memcpy(acomp_ctx->buffers[0], src, entry->length);
+ src = acomp_ctx->buffers[0];
zpool_unmap_handle(zpool, entry->handle);
}
sg_init_one(&input, src, entry->length);
sg_init_table(&output, 1);
sg_set_folio(&output, folio, PAGE_SIZE, 0);
- acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, PAGE_SIZE);
- BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait));
- BUG_ON(acomp_ctx->req->dlen != PAGE_SIZE);
+ acomp_request_set_params(acomp_ctx->reqs[0], &input, &output, entry->length, PAGE_SIZE);
+ BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->reqs[0]), &acomp_ctx->wait));
+ BUG_ON(acomp_ctx->reqs[0]->dlen != PAGE_SIZE);
mutex_unlock(&acomp_ctx->mutex);
- if (src != acomp_ctx->buffer)
+ if (src != acomp_ctx->buffers[0])
zpool_unmap_handle(zpool, entry->handle);
}
--
2.27.0
