| Message ID | 20250303084724.6490-14-kanchana.p.sridhar@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | zswap IAA compress batching | expand |
On Mon, Mar 03, 2025 at 12:47:23AM -0800, Kanchana P Sridhar wrote: > This patch adds support for the per-CPU acomp_ctx to track multiple > compression/decompression requests and multiple compression destination > buffers. The zswap_cpu_comp_prepare() CPU onlining code will get the > maximum batch-size the compressor supports. If so, it will allocate the > necessary batching resources. > > However, zswap does not use more than one request yet. Follow-up patches > will actually utilize the multiple acomp_ctx requests/buffers for batch > compression/decompression of multiple pages. > > The newly added ZSWAP_MAX_BATCH_SIZE limits the amount of extra memory used > for batching. There is a small extra memory overhead of allocating the > "reqs" and "buffers" arrays for compressors that do not support batching. That's two pointers per-CPU (i.e. 16 bytes on x86_64), right? Please call that out in the commit log. > > Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> > --- > mm/zswap.c | 99 +++++++++++++++++++++++++++++++++++++----------------- > 1 file changed, 69 insertions(+), 30 deletions(-) > > diff --git a/mm/zswap.c b/mm/zswap.c > index cff96df1df8b..fae59d6d5147 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -78,6 +78,16 @@ 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. > + * This limit exists because we preallocate enough requests and buffers > + * in the per-cpu acomp_ctx accordingly. Hence, a higher limit means higher > + * memory usage. > + */ That's too verbose. Let's do something like: /* Limit the batch size to limit per-CPU memory usage for reqs and buffers */ #define ZSWAP_MAX_BATCH_SIZE 8U > +#define ZSWAP_MAX_BATCH_SIZE 8U > + > static int zswap_setup(void); > > /* Enable/disable zswap */ > @@ -143,8 +153,8 @@ bool zswap_never_enabled(void) > > struct crypto_acomp_ctx { > struct crypto_acomp *acomp; > - struct acomp_req *req; > - u8 *buffer; > + struct acomp_req **reqs; > + u8 **buffers; > u8 nr_reqs; > struct crypto_wait wait; > struct mutex mutex; > @@ -251,13 +261,22 @@ static void __zswap_pool_empty(struct percpu_ref *ref); > static void acomp_ctx_dealloc(struct crypto_acomp_ctx *acomp_ctx) > { > if (!IS_ERR_OR_NULL(acomp_ctx) && acomp_ctx->nr_reqs) { > + u8 i; > + > + if (acomp_ctx->reqs) { > + for (i = 0; i < acomp_ctx->nr_reqs; ++i) > + if (!IS_ERR_OR_NULL(acomp_ctx->reqs[i])) Hmm I just realized we check IS_ERR_OR_NULL() here for the requests, but only a NULL check in zswap_cpu_comp_prepare(). We also check IS_ERR_OR_NULL here for acomp, but only IS_ERR() in zswap_cpu_comp_prepare(). This doesn't make sense. Would you be able to include a patch before this one to make these consistent? I can also send a follow up patch. > + acomp_request_free(acomp_ctx->reqs[i]); Please add braces for the for loop here for readability, since the body has more than one line, even if it's technically not required. > + kfree(acomp_ctx->reqs); > + acomp_ctx->reqs = NULL; > + } > > - if (!IS_ERR_OR_NULL(acomp_ctx->req)) > - acomp_request_free(acomp_ctx->req); > - acomp_ctx->req = NULL; > - > - kfree(acomp_ctx->buffer); > - acomp_ctx->buffer = NULL; > + if (acomp_ctx->buffers) { > + for (i = 0; i < acomp_ctx->nr_reqs; ++i) > + kfree(acomp_ctx->buffers[i]); > + kfree(acomp_ctx->buffers); > + acomp_ctx->buffers = NULL; > + } > > if (!IS_ERR_OR_NULL(acomp_ctx->acomp)) > crypto_free_acomp(acomp_ctx->acomp); > @@ -271,6 +290,7 @@ 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); > int ret = -ENOMEM; > + u8 i; > > /* > * Just to be even more fail-safe against changes in assumptions and/or > @@ -292,22 +312,41 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node) > goto fail; > } > > - acomp_ctx->nr_reqs = 1; > + acomp_ctx->nr_reqs = min(ZSWAP_MAX_BATCH_SIZE, > + crypto_acomp_batch_size(acomp_ctx->acomp)); > > - acomp_ctx->req = acomp_request_alloc(acomp_ctx->acomp); > - if (!acomp_ctx->req) { > - pr_err("could not alloc crypto acomp_request %s\n", > - pool->tfm_name); > - ret = -ENOMEM; > + acomp_ctx->reqs = kcalloc_node(acomp_ctx->nr_reqs, sizeof(struct acomp_req *), > + GFP_KERNEL, cpu_to_node(cpu)); > + if (!acomp_ctx->reqs) > goto fail; > + > + for (i = 0; i < acomp_ctx->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); > + goto fail; > + } > } > > - acomp_ctx->buffer = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu)); > - if (!acomp_ctx->buffer) { > - ret = -ENOMEM; > + acomp_ctx->buffers = kcalloc_node(acomp_ctx->nr_reqs, sizeof(u8 *), > + GFP_KERNEL, cpu_to_node(cpu)); > + if (!acomp_ctx->buffers) > goto fail; > + > + for (i = 0; i < acomp_ctx->nr_reqs; ++i) { > + acomp_ctx->buffers[i] = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, > + cpu_to_node(cpu)); > + if (!acomp_ctx->buffers[i]) > + goto fail; > } > > + /* > + * 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. > + */ I am not sure I understand. Does this say that we assume that scomp or non-poll acomp will never use batching so having a single "wait" is fine? If so, this needs to be enforced at runtime or at least have a warning, and not just mentioned in a comment, in case batching support is ever added for these. Please clarify. We should also probably merge the comments above crypto_init_wait() and acomp_request_set_callback() now. > crypto_init_wait(&acomp_ctx->wait); > > /*
> -----Original Message----- > From: Yosry Ahmed <yosry.ahmed@linux.dev> > Sent: Thursday, March 6, 2025 12:01 PM > To: Sridhar, Kanchana P <kanchana.p.sridhar@intel.com> > Cc: linux-kernel@vger.kernel.org; linux-mm@kvack.org; > hannes@cmpxchg.org; nphamcs@gmail.com; chengming.zhou@linux.dev; > usamaarif642@gmail.com; ryan.roberts@arm.com; 21cnbao@gmail.com; > ying.huang@linux.alibaba.com; akpm@linux-foundation.org; linux- > crypto@vger.kernel.org; herbert@gondor.apana.org.au; > davem@davemloft.net; clabbe@baylibre.com; ardb@kernel.org; > ebiggers@google.com; surenb@google.com; Accardi, Kristen C > <kristen.c.accardi@intel.com>; Feghali, Wajdi K <wajdi.k.feghali@intel.com>; > Gopal, Vinodh <vinodh.gopal@intel.com> > Subject: Re: [PATCH v8 13/14] mm: zswap: Allocate pool batching resources if > the compressor supports batching. > > On Mon, Mar 03, 2025 at 12:47:23AM -0800, Kanchana P Sridhar wrote: > > This patch adds support for the per-CPU acomp_ctx to track multiple > > compression/decompression requests and multiple compression destination > > buffers. The zswap_cpu_comp_prepare() CPU onlining code will get the > > maximum batch-size the compressor supports. If so, it will allocate the > > necessary batching resources. > > > > However, zswap does not use more than one request yet. Follow-up > patches > > will actually utilize the multiple acomp_ctx requests/buffers for batch > > compression/decompression of multiple pages. > > > > The newly added ZSWAP_MAX_BATCH_SIZE limits the amount of extra > memory used > > for batching. There is a small extra memory overhead of allocating the > > "reqs" and "buffers" arrays for compressors that do not support batching. > > That's two pointers per-CPU (i.e. 16 bytes on x86_64), right? Please > call that out in the commit log. Yes, this is done. Thanks, Kanchana > > > > > Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> > > --- > > mm/zswap.c | 99 +++++++++++++++++++++++++++++++++++++------------- > ---- > > 1 file changed, 69 insertions(+), 30 deletions(-) > > > > diff --git a/mm/zswap.c b/mm/zswap.c > > index cff96df1df8b..fae59d6d5147 100644 > > --- a/mm/zswap.c > > +++ b/mm/zswap.c > > @@ -78,6 +78,16 @@ 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. > > + * This limit exists because we preallocate enough requests and buffers > > + * in the per-cpu acomp_ctx accordingly. Hence, a higher limit means > higher > > + * memory usage. > > + */ > > That's too verbose. Let's do something like: > > /* Limit the batch size to limit per-CPU memory usage for reqs and buffers */ > #define ZSWAP_MAX_BATCH_SIZE 8U Addressed in v9. > > > +#define ZSWAP_MAX_BATCH_SIZE 8U > > + > > static int zswap_setup(void); > > > > /* Enable/disable zswap */ > > @@ -143,8 +153,8 @@ bool zswap_never_enabled(void) > > > > struct crypto_acomp_ctx { > > struct crypto_acomp *acomp; > > - struct acomp_req *req; > > - u8 *buffer; > > + struct acomp_req **reqs; > > + u8 **buffers; > > u8 nr_reqs; > > struct crypto_wait wait; > > struct mutex mutex; > > @@ -251,13 +261,22 @@ static void __zswap_pool_empty(struct > percpu_ref *ref); > > static void acomp_ctx_dealloc(struct crypto_acomp_ctx *acomp_ctx) > > { > > if (!IS_ERR_OR_NULL(acomp_ctx) && acomp_ctx->nr_reqs) { > > + u8 i; > > + > > + if (acomp_ctx->reqs) { > > + for (i = 0; i < acomp_ctx->nr_reqs; ++i) > > + if (!IS_ERR_OR_NULL(acomp_ctx->reqs[i])) > > Hmm I just realized we check IS_ERR_OR_NULL() here for the requests, but > only a NULL check in zswap_cpu_comp_prepare(). We also check > IS_ERR_OR_NULL here for acomp, but only IS_ERR() in > zswap_cpu_comp_prepare(). > > This doesn't make sense. Would you be able to include a patch before > this one to make these consistent? I can also send a follow up patch. No worries, I have included this as patch 16 in the v9 series. > > > + acomp_request_free(acomp_ctx- > >reqs[i]); > > Please add braces for the for loop here for readability, since the body > has more than one line, even if it's technically not required. Done. > > > + kfree(acomp_ctx->reqs); > > + acomp_ctx->reqs = NULL; > > + } > > > > - if (!IS_ERR_OR_NULL(acomp_ctx->req)) > > - acomp_request_free(acomp_ctx->req); > > - acomp_ctx->req = NULL; > > - > > - kfree(acomp_ctx->buffer); > > - acomp_ctx->buffer = NULL; > > + if (acomp_ctx->buffers) { > > + for (i = 0; i < acomp_ctx->nr_reqs; ++i) > > + kfree(acomp_ctx->buffers[i]); > > + kfree(acomp_ctx->buffers); > > + acomp_ctx->buffers = NULL; > > + } > > > > if (!IS_ERR_OR_NULL(acomp_ctx->acomp)) > > crypto_free_acomp(acomp_ctx->acomp); > > @@ -271,6 +290,7 @@ 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); > > int ret = -ENOMEM; > > + u8 i; > > > > /* > > * Just to be even more fail-safe against changes in assumptions > and/or > > @@ -292,22 +312,41 @@ static int zswap_cpu_comp_prepare(unsigned int > cpu, struct hlist_node *node) > > goto fail; > > } > > > > - acomp_ctx->nr_reqs = 1; > > + acomp_ctx->nr_reqs = min(ZSWAP_MAX_BATCH_SIZE, > > + crypto_acomp_batch_size(acomp_ctx- > >acomp)); > > > > - acomp_ctx->req = acomp_request_alloc(acomp_ctx->acomp); > > - if (!acomp_ctx->req) { > > - pr_err("could not alloc crypto acomp_request %s\n", > > - pool->tfm_name); > > - ret = -ENOMEM; > > + acomp_ctx->reqs = kcalloc_node(acomp_ctx->nr_reqs, sizeof(struct > acomp_req *), > > + GFP_KERNEL, cpu_to_node(cpu)); > > + if (!acomp_ctx->reqs) > > goto fail; > > + > > + for (i = 0; i < acomp_ctx->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); > > + goto fail; > > + } > > } > > > > - acomp_ctx->buffer = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, > cpu_to_node(cpu)); > > - if (!acomp_ctx->buffer) { > > - ret = -ENOMEM; > > + acomp_ctx->buffers = kcalloc_node(acomp_ctx->nr_reqs, sizeof(u8 > *), > > + GFP_KERNEL, cpu_to_node(cpu)); > > + if (!acomp_ctx->buffers) > > goto fail; > > + > > + for (i = 0; i < acomp_ctx->nr_reqs; ++i) { > > + acomp_ctx->buffers[i] = kmalloc_node(PAGE_SIZE * 2, > GFP_KERNEL, > > + cpu_to_node(cpu)); > > + if (!acomp_ctx->buffers[i]) > > + goto fail; > > } > > > > + /* > > + * 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. > > + */ > > I am not sure I understand. Does this say that we assume that scomp or > non-poll acomp will never use batching so having a single "wait" is > fine? > > If so, this needs to be enforced at runtime or at least have a warning, > and not just mentioned in a comment, in case batching support is ever > added for these. Please clarify. This was pertaining to the request chaining batching implementation and is no longer relevant. I have deleted this comment in v9, in which crypto_acomp_batch_[de]compress() do not take a "struct crypto_wait" parameter. > > We should also probably merge the comments above crypto_init_wait() and > acomp_request_set_callback() now. Done, and clarified the use of the single "wait" in zswap calls to crypto_acomp_[de]compress(). Thanks, Kanchana > > > crypto_init_wait(&acomp_ctx->wait); > > > > /*
diff --git a/mm/zswap.c b/mm/zswap.c index cff96df1df8b..fae59d6d5147 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -78,6 +78,16 @@ 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. + * This limit exists because we preallocate enough requests and buffers + * in the per-cpu acomp_ctx accordingly. Hence, a higher limit means higher + * memory usage. + */ +#define ZSWAP_MAX_BATCH_SIZE 8U + static int zswap_setup(void); /* Enable/disable zswap */ @@ -143,8 +153,8 @@ bool zswap_never_enabled(void) struct crypto_acomp_ctx { struct crypto_acomp *acomp; - struct acomp_req *req; - u8 *buffer; + struct acomp_req **reqs; + u8 **buffers; u8 nr_reqs; struct crypto_wait wait; struct mutex mutex; @@ -251,13 +261,22 @@ static void __zswap_pool_empty(struct percpu_ref *ref); static void acomp_ctx_dealloc(struct crypto_acomp_ctx *acomp_ctx) { if (!IS_ERR_OR_NULL(acomp_ctx) && acomp_ctx->nr_reqs) { + u8 i; + + if (acomp_ctx->reqs) { + 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); + acomp_ctx->reqs = NULL; + } - if (!IS_ERR_OR_NULL(acomp_ctx->req)) - acomp_request_free(acomp_ctx->req); - acomp_ctx->req = NULL; - - kfree(acomp_ctx->buffer); - acomp_ctx->buffer = NULL; + if (acomp_ctx->buffers) { + for (i = 0; i < acomp_ctx->nr_reqs; ++i) + kfree(acomp_ctx->buffers[i]); + kfree(acomp_ctx->buffers); + acomp_ctx->buffers = NULL; + } if (!IS_ERR_OR_NULL(acomp_ctx->acomp)) crypto_free_acomp(acomp_ctx->acomp); @@ -271,6 +290,7 @@ 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); int ret = -ENOMEM; + u8 i; /* * Just to be even more fail-safe against changes in assumptions and/or @@ -292,22 +312,41 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node) goto fail; } - acomp_ctx->nr_reqs = 1; + acomp_ctx->nr_reqs = min(ZSWAP_MAX_BATCH_SIZE, + crypto_acomp_batch_size(acomp_ctx->acomp)); - acomp_ctx->req = acomp_request_alloc(acomp_ctx->acomp); - if (!acomp_ctx->req) { - pr_err("could not alloc crypto acomp_request %s\n", - pool->tfm_name); - ret = -ENOMEM; + acomp_ctx->reqs = kcalloc_node(acomp_ctx->nr_reqs, sizeof(struct acomp_req *), + GFP_KERNEL, cpu_to_node(cpu)); + if (!acomp_ctx->reqs) goto fail; + + for (i = 0; i < acomp_ctx->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); + goto fail; + } } - acomp_ctx->buffer = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu)); - if (!acomp_ctx->buffer) { - ret = -ENOMEM; + acomp_ctx->buffers = kcalloc_node(acomp_ctx->nr_reqs, sizeof(u8 *), + GFP_KERNEL, cpu_to_node(cpu)); + if (!acomp_ctx->buffers) goto fail; + + for (i = 0; i < acomp_ctx->nr_reqs; ++i) { + acomp_ctx->buffers[i] = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, + cpu_to_node(cpu)); + if (!acomp_ctx->buffers[i]) + goto fail; } + /* + * 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); /* @@ -315,7 +354,7 @@ static int zswap_cpu_comp_prepare(unsigned int cpu, struct hlist_node *node) * 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(acomp_ctx->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->is_sleepable = acomp_is_async(acomp_ctx->acomp); @@ -407,8 +446,8 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor) struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu); acomp_ctx->acomp = NULL; - acomp_ctx->req = NULL; - acomp_ctx->buffer = NULL; + acomp_ctx->reqs = NULL; + acomp_ctx->buffers = NULL; acomp_ctx->__online = false; acomp_ctx->nr_reqs = 0; mutex_init(&acomp_ctx->mutex); @@ -1026,7 +1065,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, u8 *dst; acomp_ctx = acomp_ctx_get_cpu_lock(pool); - dst = acomp_ctx->buffer; + dst = acomp_ctx->buffers[0]; sg_init_table(&input, 1); sg_set_page(&input, page, PAGE_SIZE, 0); @@ -1036,7 +1075,7 @@ 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, @@ -1050,8 +1089,8 @@ 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; @@ -1102,19 +1141,19 @@ 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); - if (src != acomp_ctx->buffer) + if (src != acomp_ctx->buffers[0]) zpool_unmap_handle(zpool, entry->handle); acomp_ctx_put_unlock(acomp_ctx); }
This patch adds support for the per-CPU acomp_ctx to track multiple compression/decompression requests and multiple compression destination buffers. The zswap_cpu_comp_prepare() CPU onlining code will get the maximum batch-size the compressor supports. If so, it will allocate the necessary batching resources. However, zswap does not use more than one request yet. Follow-up patches will actually utilize the multiple acomp_ctx requests/buffers for batch compression/decompression of multiple pages. The newly added ZSWAP_MAX_BATCH_SIZE limits the amount of extra memory used for batching. There is a small extra memory overhead of allocating the "reqs" and "buffers" arrays for compressors that do not support batching. Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> --- mm/zswap.c | 99 +++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 69 insertions(+), 30 deletions(-)