| Message ID | 20241018064101.336232-5-kanchana.p.sridhar@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | zswap IAA compress batching | expand |
On Thu, Oct 17, 2024 at 11:41 PM Kanchana P Sridhar <kanchana.p.sridhar@intel.com> wrote: > > If the crypto_acomp has a poll interface registered, zswap_compress() > and zswap_decompress() will submit the acomp_req, and then poll() for a > successful completion/error status in a busy-wait loop. This allows an > asynchronous way to manage (potentially multiple) acomp_reqs without > the use of interrupts, which is supported in the iaa_crypto driver. > > This enables us to implement batch submission of multiple > compression/decompression jobs to the Intel IAA hardware accelerator, > which will process them in parallel; followed by polling the batch's > acomp_reqs for completion status. > > Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> > --- > mm/zswap.c | 51 +++++++++++++++++++++++++++++++++++++++------------ > 1 file changed, 39 insertions(+), 12 deletions(-) > > diff --git a/mm/zswap.c b/mm/zswap.c > index f6316b66fb23..948c9745ee57 100644 > --- a/mm/zswap.c > +++ b/mm/zswap.c > @@ -910,18 +910,34 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, > 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, zswap 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 zwap. > - * but in different threads running on different cpu, we have different > - * acomp instance, so multiple threads can do (de)compression in parallel. > + * If the crypto_acomp provides an asynchronous poll() interface, > + * submit the descriptor and poll for a completion status. > + * > + * It maybe looks a little bit silly that we send an asynchronous > + * request, then wait for its completion in a busy-wait poll loop, or, > + * 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, zswap 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 zswap. > + * 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); > + if (acomp_ctx->acomp->poll) { > + comp_ret = crypto_acomp_compress(acomp_ctx->req); > + if (comp_ret == -EINPROGRESS) { > + do { > + comp_ret = crypto_acomp_poll(acomp_ctx->req); > + if (comp_ret && comp_ret != -EAGAIN) > + break; > + } while (comp_ret); > + } > + } else { > + comp_ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait); > + } > + Is Herbert suggesting that crypto_wait_req(crypto_acomp_compress(..)) essentially do the poll internally for IAA, and hence this change can be dropped? > dlen = acomp_ctx->req->dlen; > if (comp_ret) > goto unlock; > @@ -959,6 +975,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) > struct scatterlist input, output; > struct crypto_acomp_ctx *acomp_ctx; > u8 *src; > + int ret; > > acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); > mutex_lock(&acomp_ctx->mutex); > @@ -984,7 +1001,17 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) > 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)); > + if (acomp_ctx->acomp->poll) { > + ret = crypto_acomp_decompress(acomp_ctx->req); > + if (ret == -EINPROGRESS) { > + do { > + ret = crypto_acomp_poll(acomp_ctx->req); > + BUG_ON(ret && ret != -EAGAIN); > + } while (ret); > + } > + } else { > + BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait)); > + } > BUG_ON(acomp_ctx->req->dlen != PAGE_SIZE); > mutex_unlock(&acomp_ctx->mutex); > > -- > 2.27.0 >
Hi Yosry, > -----Original Message----- > From: Yosry Ahmed <yosryahmed@google.com> > Sent: Tuesday, October 22, 2024 5:49 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; Huang, Ying > <ying.huang@intel.com>; 21cnbao@gmail.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>; zanussi@kernel.org; viro@zeniv.linux.org.uk; > brauner@kernel.org; jack@suse.cz; mcgrof@kernel.org; kees@kernel.org; > joel.granados@kernel.org; bfoster@redhat.com; willy@infradead.org; linux- > fsdevel@vger.kernel.org; Feghali, Wajdi K <wajdi.k.feghali@intel.com>; Gopal, > Vinodh <vinodh.gopal@intel.com> > Subject: Re: [RFC PATCH v1 04/13] mm: zswap: > zswap_compress()/decompress() can submit, then poll an acomp_req. > > On Thu, Oct 17, 2024 at 11:41 PM Kanchana P Sridhar > <kanchana.p.sridhar@intel.com> wrote: > > > > If the crypto_acomp has a poll interface registered, zswap_compress() > > and zswap_decompress() will submit the acomp_req, and then poll() for a > > successful completion/error status in a busy-wait loop. This allows an > > asynchronous way to manage (potentially multiple) acomp_reqs without > > the use of interrupts, which is supported in the iaa_crypto driver. > > > > This enables us to implement batch submission of multiple > > compression/decompression jobs to the Intel IAA hardware accelerator, > > which will process them in parallel; followed by polling the batch's > > acomp_reqs for completion status. > > > > Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> > > --- > > mm/zswap.c | 51 +++++++++++++++++++++++++++++++++++++++---------- > -- > > 1 file changed, 39 insertions(+), 12 deletions(-) > > > > diff --git a/mm/zswap.c b/mm/zswap.c > > index f6316b66fb23..948c9745ee57 100644 > > --- a/mm/zswap.c > > +++ b/mm/zswap.c > > @@ -910,18 +910,34 @@ static bool zswap_compress(struct page *page, > struct zswap_entry *entry, > > 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, zswap 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 zwap. > > - * but in different threads running on different cpu, we have different > > - * acomp instance, so multiple threads can do (de)compression in > parallel. > > + * If the crypto_acomp provides an asynchronous poll() interface, > > + * submit the descriptor and poll for a completion status. > > + * > > + * It maybe looks a little bit silly that we send an asynchronous > > + * request, then wait for its completion in a busy-wait poll loop, or, > > + * 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, zswap 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 zswap. > > + * 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); > > + if (acomp_ctx->acomp->poll) { > > + comp_ret = crypto_acomp_compress(acomp_ctx->req); > > + if (comp_ret == -EINPROGRESS) { > > + do { > > + comp_ret = crypto_acomp_poll(acomp_ctx->req); > > + if (comp_ret && comp_ret != -EAGAIN) > > + break; > > + } while (comp_ret); > > + } > > + } else { > > + comp_ret = > crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx- > >wait); > > + } > > + > > Is Herbert suggesting that crypto_wait_req(crypto_acomp_compress(..)) > essentially do the poll internally for IAA, and hence this change can > be dropped? Yes, you're right. I plan to submit a v2 shortly with Herbert's suggestion. Thanks, Kanchana > > > dlen = acomp_ctx->req->dlen; > > if (comp_ret) > > goto unlock; > > @@ -959,6 +975,7 @@ static void zswap_decompress(struct zswap_entry > *entry, struct folio *folio) > > struct scatterlist input, output; > > struct crypto_acomp_ctx *acomp_ctx; > > u8 *src; > > + int ret; > > > > acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); > > mutex_lock(&acomp_ctx->mutex); > > @@ -984,7 +1001,17 @@ static void zswap_decompress(struct > zswap_entry *entry, struct folio *folio) > > 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)); > > + if (acomp_ctx->acomp->poll) { > > + ret = crypto_acomp_decompress(acomp_ctx->req); > > + if (ret == -EINPROGRESS) { > > + do { > > + ret = crypto_acomp_poll(acomp_ctx->req); > > + BUG_ON(ret && ret != -EAGAIN); > > + } while (ret); > > + } > > + } else { > > + > BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), > &acomp_ctx->wait)); > > + } > > BUG_ON(acomp_ctx->req->dlen != PAGE_SIZE); > > mutex_unlock(&acomp_ctx->mutex); > > > > -- > > 2.27.0 > >
diff --git a/mm/zswap.c b/mm/zswap.c index f6316b66fb23..948c9745ee57 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -910,18 +910,34 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, 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, zswap 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 zwap. - * but in different threads running on different cpu, we have different - * acomp instance, so multiple threads can do (de)compression in parallel. + * If the crypto_acomp provides an asynchronous poll() interface, + * submit the descriptor and poll for a completion status. + * + * It maybe looks a little bit silly that we send an asynchronous + * request, then wait for its completion in a busy-wait poll loop, or, + * 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, zswap 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 zswap. + * 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); + if (acomp_ctx->acomp->poll) { + comp_ret = crypto_acomp_compress(acomp_ctx->req); + if (comp_ret == -EINPROGRESS) { + do { + comp_ret = crypto_acomp_poll(acomp_ctx->req); + if (comp_ret && comp_ret != -EAGAIN) + break; + } while (comp_ret); + } + } else { + comp_ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait); + } + dlen = acomp_ctx->req->dlen; if (comp_ret) goto unlock; @@ -959,6 +975,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) struct scatterlist input, output; struct crypto_acomp_ctx *acomp_ctx; u8 *src; + int ret; acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); @@ -984,7 +1001,17 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) 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)); + if (acomp_ctx->acomp->poll) { + ret = crypto_acomp_decompress(acomp_ctx->req); + if (ret == -EINPROGRESS) { + do { + ret = crypto_acomp_poll(acomp_ctx->req); + BUG_ON(ret && ret != -EAGAIN); + } while (ret); + } + } else { + BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait)); + } BUG_ON(acomp_ctx->req->dlen != PAGE_SIZE); mutex_unlock(&acomp_ctx->mutex);
If the crypto_acomp has a poll interface registered, zswap_compress() and zswap_decompress() will submit the acomp_req, and then poll() for a successful completion/error status in a busy-wait loop. This allows an asynchronous way to manage (potentially multiple) acomp_reqs without the use of interrupts, which is supported in the iaa_crypto driver. This enables us to implement batch submission of multiple compression/decompression jobs to the Intel IAA hardware accelerator, which will process them in parallel; followed by polling the batch's acomp_reqs for completion status. Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> --- mm/zswap.c | 51 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 39 insertions(+), 12 deletions(-)