| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <SJ2PR11MB8472581BC9FAAC1048C6D8F7C9A9A@SJ2PR11MB8472.namprd11.prod.outlook.com> Date: Fri, 19 Dec 2025 19:03:13 +0000 From: "Sridhar, Kanchana P" <kanchana.p.sridhar@...el.com> To: Yosry Ahmed <yosry.ahmed@...ux.dev> CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "linux-mm@...ck.org" <linux-mm@...ck.org>, "hannes@...xchg.org" <hannes@...xchg.org>, "nphamcs@...il.com" <nphamcs@...il.com>, "chengming.zhou@...ux.dev" <chengming.zhou@...ux.dev>, "usamaarif642@...il.com" <usamaarif642@...il.com>, "ryan.roberts@....com" <ryan.roberts@....com>, "21cnbao@...il.com" <21cnbao@...il.com>, "ying.huang@...ux.alibaba.com" <ying.huang@...ux.alibaba.com>, "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>, "senozhatsky@...omium.org" <senozhatsky@...omium.org>, "sj@...nel.org" <sj@...nel.org>, "kasong@...cent.com" <kasong@...cent.com>, "linux-crypto@...r.kernel.org" <linux-crypto@...r.kernel.org>, "herbert@...dor.apana.org.au" <herbert@...dor.apana.org.au>, "davem@...emloft.net" <davem@...emloft.net>, "clabbe@...libre.com" <clabbe@...libre.com>, "ardb@...nel.org" <ardb@...nel.org>, "ebiggers@...gle.com" <ebiggers@...gle.com>, "surenb@...gle.com" <surenb@...gle.com>, "Accardi, Kristen C" <kristen.c.accardi@...el.com>, "Gomes, Vinicius" <vinicius.gomes@...el.com>, "Feghali, Wajdi K" <wajdi.k.feghali@...el.com>, "Gopal, Vinodh" <vinodh.gopal@...el.com>, "Sridhar, Kanchana P" <kanchana.p.sridhar@...el.com> Subject: RE: [PATCH v13 22/22] mm: zswap: Batched zswap_compress() with compress batching of large folios. > -----Original Message----- > From: Yosry Ahmed <yosry.ahmed@...ux.dev> > Sent: Friday, December 19, 2025 7:26 AM > To: Sridhar, Kanchana P <kanchana.p.sridhar@...el.com> > Cc: linux-kernel@...r.kernel.org; linux-mm@...ck.org; > hannes@...xchg.org; nphamcs@...il.com; chengming.zhou@...ux.dev; > usamaarif642@...il.com; ryan.roberts@....com; 21cnbao@...il.com; > ying.huang@...ux.alibaba.com; akpm@...ux-foundation.org; > senozhatsky@...omium.org; sj@...nel.org; kasong@...cent.com; linux- > crypto@...r.kernel.org; herbert@...dor.apana.org.au; > davem@...emloft.net; clabbe@...libre.com; ardb@...nel.org; > ebiggers@...gle.com; surenb@...gle.com; Accardi, Kristen C > <kristen.c.accardi@...el.com>; Gomes, Vinicius <vinicius.gomes@...el.com>; > Feghali, Wajdi K <wajdi.k.feghali@...el.com>; Gopal, Vinodh > <vinodh.gopal@...el.com> > Subject: Re: [PATCH v13 22/22] mm: zswap: Batched zswap_compress() with > compress batching of large folios. > > On Fri, Dec 19, 2025 at 02:29:15AM +0000, Sridhar, Kanchana P wrote: > > > > > -----Original Message----- > > > From: Yosry Ahmed <yosry.ahmed@...ux.dev> > > > Sent: Thursday, November 13, 2025 4:46 PM > > > To: Sridhar, Kanchana P <kanchana.p.sridhar@...el.com> > > > Cc: linux-kernel@...r.kernel.org; linux-mm@...ck.org; > > > hannes@...xchg.org; nphamcs@...il.com; > chengming.zhou@...ux.dev; > > > usamaarif642@...il.com; ryan.roberts@....com; 21cnbao@...il.com; > > > ying.huang@...ux.alibaba.com; akpm@...ux-foundation.org; > > > senozhatsky@...omium.org; sj@...nel.org; kasong@...cent.com; linux- > > > crypto@...r.kernel.org; herbert@...dor.apana.org.au; > > > davem@...emloft.net; clabbe@...libre.com; ardb@...nel.org; > > > ebiggers@...gle.com; surenb@...gle.com; Accardi, Kristen C > > > <kristen.c.accardi@...el.com>; Gomes, Vinicius > <vinicius.gomes@...el.com>; > > > Feghali, Wajdi K <wajdi.k.feghali@...el.com>; Gopal, Vinodh > > > <vinodh.gopal@...el.com> > > > Subject: Re: [PATCH v13 22/22] mm: zswap: Batched zswap_compress() > with > > > compress batching of large folios. > > [...] > > > > > > Architectural considerations for the zswap batching framework: > > > > > > > > > > > > > > > ============================================================== > > > > > > We have designed the zswap batching framework to be > > > > > > hardware-agnostic. It has no dependencies on Intel-specific features > > > and > > > > > > can be leveraged by any hardware accelerator or software-based > > > > > > compressor. In other words, the framework is open and inclusive by > > > > > > design. > > > > > > > > > > > > Other ongoing work that can use batching: > > > > > > ========================================= > > > > > > This patch-series demonstrates the performance benefits of > compress > > > > > > batching when used in zswap_store() of large folios. > shrink_folio_list() > > > > > > "reclaim batching" of any-order folios is the major next work that > uses > > > > > > the zswap compress batching framework: our testing of > > > kernel_compilation > > > > > > with writeback and the zswap shrinker indicates 10X fewer pages get > > > > > > written back when we reclaim 32 folios as a batch, as compared to > one > > > > > > folio at a time: this is with deflate-iaa and with zstd. We expect to > > > > > > submit a patch-series with this data and the resulting performance > > > > > > improvements shortly. Reclaim batching relieves memory pressure > > > faster > > > > > > than reclaiming one folio at a time, hence alleviates the need to scan > > > > > > slab memory for writeback. > > > > > > > > > > > > Nhat has given ideas on using batching with the ongoing kcompressd > > > work, > > > > > > as well as beneficially using decompression batching & block IO > batching > > > > > > to improve zswap writeback efficiency. > > > > > > > > > > > > Experiments that combine zswap compress batching, reclaim > batching, > > > > > > swapin_readahead() decompression batching of prefetched pages, > and > > > > > > writeback batching show that 0 pages are written back with deflate- > iaa > > > > > > and zstd. For comparison, the baselines for these compressors see > > > > > > 200K-800K pages written to disk (kernel compilation 'allmod' config). > > > > > > > > > > > > To summarize, these are future clients of the batching framework: > > > > > > > > > > > > - shrink_folio_list() reclaim batching of multiple folios: > > > > > > Implemented, will submit patch-series. > > > > > > - zswap writeback with decompress batching: > > > > > > Implemented, will submit patch-series. > > > > > > - zram: > > > > > > Implemented, will submit patch-series. > > > > > > - kcompressd: > > > > > > Not yet implemented. > > > > > > - file systems: > > > > > > Not yet implemented. > > > > > > - swapin_readahead() decompression batching of prefetched > pages: > > > > > > Implemented, will submit patch-series. > > > > > > > > > > > > Additionally, any place we have folios that need to be compressed, > can > > > > > > potentially be parallelized. > > > > [...] > > > > > For example, you should remove mentions of ongoing work and future > work, > > > simply because things change and they may not land. Just briefly > > > mentioning that there are future use cases (with maybe an example) is > > > sufficient. > > > > Hi Yosry, > > > > The mentions of ongoing/future work were included as per Andrew's > suggestion. > > Hence, I would like to keep these in the commit log. Hope this is Ok with > you? > > We can keep them, but not in the detail they are currently in, and > avoiding mentioning what is implemented or not implemented yet because > it's not very relevant to the patch imo. > > So maybe focus on the fact that the compression batching can be used for > other use cases like batching decompression in zswap writeback, batching > compression in zram, batch compression of different folios during > reclaim, etc -- without going too much into detail because these details > will probably change when these extensions are proposed. Sure, this sounds good, thanks! > > > > > > Thanks, > > Kanchana > >
Powered by blists - more mailing lists