| Message ID | 20241018064101.336232-1-kanchana.p.sridhar@intel.com |
|---|---|
| Headers | show |
| Series | zswap IAA compress batching | expand |
This patch enables the use of Intel IAA hardware compression acceleration
to reclaim a batch of folios in shrink_folio_list(). This results in
reclaim throughput and workload/sys performance improvements.
The earlier patches on compress batching deployed multiple IAA compress
engines for compressing up to SWAP_CRYPTO_SUB_BATCH_SIZE pages within a
large folio that is being stored in zswap_store(). This patch further
propagates the efficiency improvements demonstrated with IAA "batching
within folios", to vmscan "batching of folios" which will also use
batching within folios using the extensible architecture of
the __zswap_store_batch_core() procedure added earlier, that accepts
an array of folios.
A plug mechanism is introduced in swap_writepage() to aggregate a batch of
up to vm.compress-batchsize ([1, 32]) folios before processing the plug.
The plug will be processed if any of the following is true:
1) The plug has vm.compress-batchsize folios. If the system has Intel IAA,
"sysctl vm.compress-batchsize" can be configured to be in [1, 32]. On
systems without IAA, or if CONFIG_ZSWAP_STORE_BATCHING_ENABLED is not
set, "sysctl vm.compress-batchsize" can only be 1.
2) A folio of a different swap type or folio_nid as the current folios in
the plug, needs to be added to the plug.
3) A pmd-mappable folio needs to be swapped out. In this case, the
existing folios in the plug are processed. The pmd-mappable folio is
swapped out (zswap_store() will batch compress
SWAP_CRYPTO_SUB_BATCH_SIZE pages in the pmd-mappable folio if system
has IAA) in a batch of its own.
On Thu, Oct 17, 2024 at 11:40:49PM -0700, Kanchana P Sridhar wrote: > For async compress/decompress, provide a way for the caller to poll > for compress/decompress completion, rather than wait for an interrupt > to signal completion. > > Callers can submit a compress/decompress using crypto_acomp_compress > and decompress and rather than wait on a completion, call > crypto_acomp_poll() to check for completion. > > This is useful for hardware accelerators where the overhead of > interrupts and waiting for completions is too expensive. Typically > the compress/decompress hw operations complete very quickly and in the > vast majority of cases, adding the overhead of interrupt handling and > waiting for completions simply adds unnecessary delays and cancels the > gains of using the hw acceleration. > > Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> > Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> > --- > crypto/acompress.c | 1 + > include/crypto/acompress.h | 18 ++++++++++++++++++ > include/crypto/internal/acompress.h | 1 + > 3 files changed, 20 insertions(+) How about just adding a request flag that tells the driver to make the request synchronous if possible? Something like #define CRYPTO_ACOMP_REQ_POLL 0x00000001 Cheers,
On Fri, Oct 18, 2024 at 11:01:10PM +0000, Sridhar, Kanchana P wrote: > > Thanks for your code review comments. Are you referring to how the > async/poll interface is enabled at the level of say zswap (by setting a > flag in the acomp_req), followed by the iaa_crypto driver testing for > the flag and submitting the request and returning -EINPROGRESS. > Wouldn't we still need a separate API to do the polling? Correct me if I'm wrong, but I think what you want to do is this: crypto_acomp_compress(req) crypto_acomp_poll(req) So instead of adding this interface, where the poll essentially turns the request synchronous, just move this logic into the driver, based on a flag bit in req. Cheers,
> -----Original Message----- > From: Herbert Xu <herbert@gondor.apana.org.au> > Sent: Friday, October 18, 2024 5:20 PM > To: Sridhar, Kanchana P <kanchana.p.sridhar@intel.com> > Cc: linux-kernel@vger.kernel.org; linux-mm@kvack.org; > hannes@cmpxchg.org; yosryahmed@google.com; 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; 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 01/13] crypto: acomp - Add a poll() operation to > acomp_alg and acomp_req > > On Fri, Oct 18, 2024 at 11:01:10PM +0000, Sridhar, Kanchana P wrote: > > > > Thanks for your code review comments. Are you referring to how the > > async/poll interface is enabled at the level of say zswap (by setting a > > flag in the acomp_req), followed by the iaa_crypto driver testing for > > the flag and submitting the request and returning -EINPROGRESS. > > Wouldn't we still need a separate API to do the polling? > > Correct me if I'm wrong, but I think what you want to do is this: > > crypto_acomp_compress(req) > crypto_acomp_poll(req) > > So instead of adding this interface, where the poll essentially > turns the request synchronous, just move this logic into the driver, > based on a flag bit in req. Thanks Herbert, for this suggestion. I understand this better now, and will work with Kristen for addressing this in v2. Thanks, Kanchana > > Cheers, > -- > Email: Herbert Xu <herbert@gondor.apana.org.au> > Home Page: http://gondor.apana.org.au/~herbert/ > PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
> -----Original Message----- > From: Yosry Ahmed <yosryahmed@google.com> > Sent: Wednesday, October 23, 2024 11:16 AM > 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 00/13] zswap IAA compress batching > > On Tue, Oct 22, 2024 at 7:53 PM Sridhar, Kanchana P > <kanchana.p.sridhar@intel.com> wrote: > > > > Hi Yosry, > > > > > -----Original Message----- > > > From: Yosry Ahmed <yosryahmed@google.com> > > > Sent: Tuesday, October 22, 2024 5:57 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 00/13] zswap IAA compress batching > > > > > > On Thu, Oct 17, 2024 at 11:41 PM Kanchana P Sridhar > > > <kanchana.p.sridhar@intel.com> wrote: > > > > > > > > > > > > IAA Compression Batching: > > > > ========================= > > > > > > > > This RFC patch-series introduces the use of the Intel Analytics > Accelerator > > > > (IAA) for parallel compression of pages in a folio, and for batched reclaim > > > > of hybrid any-order batches of folios in shrink_folio_list(). > > > > > > > > The patch-series is organized as follows: > > > > > > > > 1) iaa_crypto driver enablers for batching: Relevant patches are tagged > > > > with "crypto:" in the subject: > > > > > > > > a) async poll crypto_acomp interface without interrupts. > > > > b) crypto testmgr acomp poll support. > > > > c) Modifying the default sync_mode to "async" and disabling > > > > verify_compress by default, to facilitate users to run IAA easily for > > > > comparison with software compressors. > > > > d) Changing the cpu-to-iaa mappings to more evenly balance cores to > IAA > > > > devices. > > > > e) Addition of a "global_wq" per IAA, which can be used as a global > > > > resource for the socket. If the user configures 2WQs per IAA device, > > > > the driver will distribute compress jobs from all cores on the > > > > socket to the "global_wqs" of all the IAA devices on that socket, in > > > > a round-robin manner. This can be used to improve compression > > > > throughput for workloads that see a lot of swapout activity. > > > > > > > > 2) Migrating zswap to use async poll in > zswap_compress()/decompress(). > > > > 3) A centralized batch compression API that can be used by swap > modules. > > > > 4) IAA compress batching within large folio zswap stores. > > > > 5) IAA compress batching of any-order hybrid folios in > > > > shrink_folio_list(). The newly added "sysctl vm.compress-batchsize" > > > > parameter can be used to configure the number of folios in [1, 32] to > > > > be reclaimed using compress batching. > > > > > > I am still digesting this series but I have some high level questions > > > that I left on some patches. My intuition though is that we should > > > drop (5) from the initial proposal as it's most controversial. > > > Batching reclaim of unrelated folios through zswap *might* make sense, > > > but it needs a broader conversation and it needs justification on its > > > own merit, without the rest of the series. > > > > Thanks for these suggestions! Sure, I can drop (5) from the initial patch-set. > > Agree also, this needs a broader discussion. > > > > I believe the 4K folios usemem30 data in this patchset does bring across > > the batching reclaim benefits to provide justification on its own merit. I > added > > the data on batching reclaim with kernel compilation as part of the 4K folios > > experiments in the IAA decompression batching patch-series [1]. > > Listing it here as well. I will make sure to add this data in subsequent revs. > > > > -------------------------------------------------------------------------- > > Kernel compilation in tmpfs/allmodconfig, 2G max memory: > > > > No large folios mm-unstable-10-16-2024 shrink_folio_list() > > batching of folios > > -------------------------------------------------------------------------- > > zswap compressor zstd deflate-iaa deflate-iaa > > vm.compress-batchsize n/a n/a 32 > > vm.page-cluster 3 3 3 > > -------------------------------------------------------------------------- > > real_sec 783.87 761.69 747.32 > > user_sec 15,750.07 15,716.69 15,728.39 > > sys_sec 6,522.32 5,725.28 5,399.44 > > Max_RSS_KB 1,872,640 1,870,848 1,874,432 > > > > zswpout 82,364,991 97,739,600 102,780,612 > > zswpin 21,303,393 27,684,166 29,016,252 > > pswpout 13 222 213 > > pswpin 12 209 202 > > pgmajfault 17,114,339 22,421,211 23,378,161 > > swap_ra 4,596,035 5,840,082 6,231,646 > > swap_ra_hit 2,903,249 3,682,444 3,940,420 > > -------------------------------------------------------------------------- > > > > The performance improvements seen does depend on compression batching > in > > the swap modules (zswap). The implementation in patch 12 in the compress > > batching series sets up this zswap compression pipeline, that takes an array > of > > folios and processes them in batches of 8 pages compressed in parallel in > hardware. > > That being said, we do see latency improvements even with reclaim > batching > > combined with zswap compress batching with zstd/lzo-rle/etc. I haven't > done a > > lot of analysis of this, but I am guessing fewer calls from the swap layer > > (swap_writepage()) into zswap could have something to do with this. If we > believe > > that batching can be the right thing to do even for the software > compressors, > > I can gather batching data with zstd for v2. > > Thanks for sharing the data. What I meant is, I think we should focus > on supporting large folio compression batching for this series, and > only present figures for this support to avoid confusion. > > Once this lands, we can discuss support for batching the compression > of different unrelated folios separately, as it spans areas beyond > just zswap and will need broader discussion. Absolutely, this makes sense, thanks Yosry! I will address this in v2. Thanks, Kanchana
IAA Compression Batching: ========================= This RFC patch-series introduces the use of the Intel Analytics Accelerator (IAA) for parallel compression of pages in a folio, and for batched reclaim of hybrid any-order batches of folios in shrink_folio_list(). The patch-series is organized as follows: 1) iaa_crypto driver enablers for batching: Relevant patches are tagged with "crypto:" in the subject: a) async poll crypto_acomp interface without interrupts. b) crypto testmgr acomp poll support. c) Modifying the default sync_mode to "async" and disabling verify_compress by default, to facilitate users to run IAA easily for comparison with software compressors. d) Changing the cpu-to-iaa mappings to more evenly balance cores to IAA devices. e) Addition of a "global_wq" per IAA, which can be used as a global resource for the socket. If the user configures 2WQs per IAA device, the driver will distribute compress jobs from all cores on the socket to the "global_wqs" of all the IAA devices on that socket, in a round-robin manner. This can be used to improve compression throughput for workloads that see a lot of swapout activity. 2) Migrating zswap to use async poll in zswap_compress()/decompress(). 3) A centralized batch compression API that can be used by swap modules. 4) IAA compress batching within large folio zswap stores. 5) IAA compress batching of any-order hybrid folios in shrink_folio_list(). The newly added "sysctl vm.compress-batchsize" parameter can be used to configure the number of folios in [1, 32] to be reclaimed using compress batching. IAA compress batching can be enabled only on platforms that have IAA, by setting this config variable: CONFIG_ZSWAP_STORE_BATCHING_ENABLED="y" The performance testing data with usemem 30 instances shows throughput gains of up to 40%, elapsed time reduction of up to 22% and sys time reduction of up to 30% with IAA compression batching. Our internal validation of IAA compress/decompress batching in highly contended Sapphire Rapids server setups with workloads running on 72 cores for ~25 minutes under stringent memory limit constraints have shown up to 50% reduction in sys time and 3.5% reduction in workload run time as compared to software compressors. System setup for testing: ========================= Testing of this patch-series was done with mm-unstable as of 10-16-2024, commit 817952b8be34, without and with this patch-series. Data was gathered on an Intel Sapphire Rapids server, dual-socket 56 cores per socket, 4 IAA devices per socket, 503 GiB RAM and 525G SSD disk partition swap. Core frequency was fixed at 2500MHz. The vm-scalability "usemem" test was run in a cgroup whose memory.high was fixed at 150G. The is no swap limit set for the cgroup. 30 usemem processes were run, each allocating and writing 10G of memory, and sleeping for 10 sec before exiting: usemem --init-time -w -O -s 10 -n 30 10g Other kernel configuration parameters: zswap compressor : deflate-iaa zswap allocator : zsmalloc vm.page-cluster : 2,4 IAA "compression verification" is disabled and the async poll acomp interface is used in the iaa_crypto driver (the defaults with this series). Performance testing (usemem30): =============================== 4K folios: deflate-iaa: ======================= ------------------------------------------------------------------------------- mm-unstable-10-16-2024 shrink_folio_list() shrink_folio_list() batching of folios batching of folios ------------------------------------------------------------------------------- zswap compressor deflate-iaa deflate-iaa deflate-iaa vm.compress-batchsize n/a 1 32 vm.page-cluster 2 2 2 ------------------------------------------------------------------------------- Total throughput 4,470,466 5,770,824 6,363,045 (KB/s) Average throughput 149,015 192,360 212,101 (KB/s) elapsed time 119.24 100.96 92.99 (sec) sys time (sec) 2,819.29 2,168.08 1,970.79 ------------------------------------------------------------------------------- memcg_high 668,185 646,357 613,421 memcg_swap_fail 0 0 0 zswpout 62,991,796 58,275,673 53,070,201 zswpin 431 415 396 pswpout 0 0 0 pswpin 0 0 0 thp_swpout 0 0 0 thp_swpout_fallback 0 0 0 pgmajfault 3,137 3,085 3,440 swap_ra 99 100 95 swap_ra_hit 42 44 45 ------------------------------------------------------------------------------- 16k/32/64k folios: deflate-iaa: =============================== All three large folio sizes 16k/32/64k were enabled to "always". ------------------------------------------------------------------------------- mm-unstable- zswap_store() + shrink_folio_list() 10-16-2024 batching of batching of folios pages in large folios ------------------------------------------------------------------------------- zswap compr deflate-iaa deflate-iaa deflate-iaa vm.compress- n/a n/a 4 8 16 batchsize vm.page- 2 2 2 2 2 cluster ------------------------------------------------------------------------------- Total throughput 7,182,198 8,448,994 8,584,728 8,729,643 8,775,944 (KB/s) Avg throughput 239,406 281,633 286,157 290,988 292,531 (KB/s) elapsed time 85.04 77.84 77.03 75.18 74.98 (sec) sys time (sec) 1,730.77 1,527.40 1,528.52 1,473.76 1,465.97 ------------------------------------------------------------------------------- memcg_high 648,125 694,188 696,004 699,728 724,887 memcg_swap_fail 1,550 2,540 1,627 1,577 1,517 zswpout 57,606,876 56,624,450 56,125,082 55,999,42 57,352,204 zswpin 421 406 422 400 437 pswpout 0 0 0 0 0 pswpin 0 0 0 0 0 thp_swpout 0 0 0 0 0 thp_swpout_fallback 0 0 0 0 0 16kB-mthp_swpout_ 0 0 0 0 0 fallback 32kB-mthp_swpout_ 0 0 0 0 0 fallback 64kB-mthp_swpout_ 1,550 2,539 1,627 1,577 1,517 fallback pgmajfault 3,102 3,126 3,473 3,454 3,134 swap_ra 107 144 109 124 181 swap_ra_hit 51 88 45 66 107 ZSWPOUT-16kB 2 3 4 4 3 ZSWPOUT-32kB 0 2 1 1 0 ZSWPOUT-64kB 3,598,889 3,536,556 3,506,134 3,498,324 3,582,921 SWPOUT-16kB 0 0 0 0 0 SWPOUT-32kB 0 0 0 0 0 SWPOUT-64kB 0 0 0 0 0 ------------------------------------------------------------------------------- 2M folios: deflate-iaa: ======================= ------------------------------------------------------------------------------- mm-unstable-10-16-2024 zswap_store() batching of pages in pmd-mappable folios ------------------------------------------------------------------------------- zswap compressor deflate-iaa deflate-iaa vm.compress-batchsize n/a n/a vm.page-cluster 2 2 ------------------------------------------------------------------------------- Total throughput 7,444,592 8,916,349 (KB/s) Average throughput 248,153 297,211 (KB/s) elapsed time 86.29 73.44 (sec) sys time (sec) 1,833.21 1,418.58 ------------------------------------------------------------------------------- memcg_high 81,786 89,905 memcg_swap_fail 82 395 zswpout 58,874,092 57,721,884 zswpin 422 458 pswpout 0 0 pswpin 0 0 thp_swpout 0 0 thp_swpout_fallback 82 394 pgmajfault 14,864 21,544 swap_ra 34,953 53,751 swap_ra_hit 34,895 53,660 ZSWPOUT-2048kB 114,815 112,269 SWPOUT-2048kB 0 0 ------------------------------------------------------------------------------- Since 4K folios account for ~0.4% of all zswapouts when pmd-mappable folios are enabled for usemem30, we cannot expect much improvement from reclaim batching. Performance testing (Kernel compilation): ========================================= As mentioned earlier, for workloads that see a lot of swapout activity, we can benefit from configuring 2 WQs per IAA device, with compress jobs from all same-socket cores being distributed toothe wq.1 of all IAAs on the socket, with the "global_wq" developed in this patch-series. Although this data includes IAA decompress batching, which will be submitted as a separate RFC patch-series, I am listing it here to quantify the benefit of distributing compress jobs among all IAAs. The kernel compilation test with "allmodconfig" is able to quantify this well: 4K folios: deflate-iaa: kernel compilation to quantify crypto patches ===================================================================== ------------------------------------------------------------------------------ IAA shrink_folio_list() compress batching and swapin_readahead() decompress batching 1WQ 2WQ (distribute compress jobs) 1 local WQ (wq.0) 1 local WQ (wq.0) + per IAA 1 global WQ (wq.1) per IAA ------------------------------------------------------------------------------ zswap compressor deflate-iaa deflate-iaa vm.compress-batchsize 32 32 vm.page-cluster 4 4 ------------------------------------------------------------------------------ real_sec 746.77 745.42 user_sec 15,732.66 15,738.85 sys_sec 5,384.14 5,247.86 Max_Res_Set_Size_KB 1,874,432 1,872,640 ------------------------------------------------------------------------------ zswpout 101,648,460 104,882,982 zswpin 27,418,319 29,428,515 pswpout 213 22 pswpin 207 6 pgmajfault 21,896,616 23,629,768 swap_ra 6,054,409 6,385,080 swap_ra_hit 3,791,628 3,985,141 ------------------------------------------------------------------------------ The iaa_crypto wq stats will show almost the same number of compress calls for wq.1 of all IAA devices. wq.0 will handle decompress calls exclusively. We see a latency reduction of 2.5% by distributing compress jobs among all IAA devices on the socket. I would greatly appreciate code review comments for the iaa_crypto driver and mm patches included in this series! Thanks, Kanchana Kanchana P Sridhar (13): crypto: acomp - Add a poll() operation to acomp_alg and acomp_req crypto: iaa - Add support for irq-less crypto async interface crypto: testmgr - Add crypto testmgr acomp poll support. mm: zswap: zswap_compress()/decompress() can submit, then poll an acomp_req. crypto: iaa - Make async mode the default. crypto: iaa - Disable iaa_verify_compress by default. crypto: iaa - Change cpu-to-iaa mappings to evenly balance cores to IAAs. crypto: iaa - Distribute compress jobs to all IAA devices on a NUMA node. mm: zswap: Config variable to enable compress batching in zswap_store(). mm: zswap: Create multiple reqs/buffers in crypto_acomp_ctx if platform has IAA. mm: swap: Add IAA batch compression API swap_crypto_acomp_compress_batch(). mm: zswap: Compress batching with Intel IAA in zswap_store() of large folios. mm: vmscan, swap, zswap: Compress batching of folios in shrink_folio_list(). crypto/acompress.c | 1 + crypto/testmgr.c | 70 +- drivers/crypto/intel/iaa/iaa_crypto_main.c | 467 +++++++++++-- include/crypto/acompress.h | 18 + include/crypto/internal/acompress.h | 1 + include/linux/fs.h | 2 + include/linux/mm.h | 8 + include/linux/writeback.h | 5 + include/linux/zswap.h | 106 +++ kernel/sysctl.c | 9 + mm/Kconfig | 12 + mm/page_io.c | 152 +++- mm/swap.c | 15 + mm/swap.h | 96 +++ mm/swap_state.c | 115 +++ mm/vmscan.c | 154 +++- mm/zswap.c | 771 +++++++++++++++++++-- 17 files changed, 1870 insertions(+), 132 deletions(-) base-commit: 817952b8be34aad40e07f6832fb9d1fc08961550