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From: Rik van Riel To: Chris Li Cc: Baoquan He , Shakeel Butt , Nhat Pham , Kairui Song , Johannes Weiner , Michal Hocko , Roman Gushchin , Yosry Ahmed , David Hildenbrand , Muchun Song , Kemeng Shi , Barry Song , YoungJun Park , Chengming Zhou , "Lorenzo Stoakes (Oracle)" , "Liam R. Howlett" , "Vlastimil Babka (SUSE)" , Mike Rapoport , Suren =?UTF-8?Q?Baghdasaryan=EF=BF=BC?= , Qi Zheng , Axel Rasmussen , Yuanchu Xie , Wei Xu , Gregory Price , Wenchao Hao , Jonathan Corbet , Hugh Dickins , Baolin Wang , Tejun Heo , Michal =?ISO-8859-1?Q?Koutn=FD?= , Shuah Khan , Kunwu Chan , Meta kernel team , Linux Memory Management List , Linux Kernel Mailing List , linux-doc@vger.kernel.org, "open list:CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)" , Andrew Morton , Kairui Song , Joshua Hahn Date: Sat, 19 Sep 2026 18:50:03 -0400 In-Reply-To: References: <7ee199ddee81bf8026688def82f78ad9db09be9e.camel@surriel.com> Autocrypt: addr=riel@surriel.com; prefer-encrypt=mutual; keydata=mQENBFIt3aUBCADCK0LicyCYyMa0E1lodCDUBf6G+6C5UXKG1jEYwQu49cc/gUBTTk33A eo2hjn4JinVaPF3zfZprnKMEGGv4dHvEOCPWiNhlz5RtqH3SKJllq2dpeMS9RqbMvDA36rlJIIo47 Z/nl6IA8MDhSqyqdnTY8z7LnQHqq16jAqwo7Ll9qALXz4yG1ZdSCmo80VPetBZZPw7WMjo+1hByv/ lvdFnLfiQ52tayuuC1r9x2qZ/SYWd2M4p/f5CLmvG9UcnkbYFsKWz8bwOBWKg1PQcaYHLx06sHGdY dIDaeVvkIfMFwAprSo5EFU+aes2VB2ZjugOTbkkW2aPSWTRsBhPHhV6dABEBAAG0HlJpayB2YW4gU mllbCA8cmllbEByZWRoYXQuY29tPokBHwQwAQIACQUCW5LcVgIdIAAKCRDOed6ShMTeg05SB/986o gEgdq4byrtaBQKFg5LWfd8e+h+QzLOg/T8mSS3dJzFXe5JBOfvYg7Bj47xXi9I5sM+I9Lu9+1XVb/ r2rGJrU1DwA09TnmyFtK76bgMF0sBEh1ECILYNQTEIemzNFwOWLZZlEhZFRJsZyX+mtEp/WQIygHV WjwuP69VJw+fPQvLOGn4j8W9QXuvhha7u1QJ7mYx4dLGHrZlHdwDsqpvWsW+3rsIqs1BBe5/Itz9o 6y9gLNtQzwmSDioV8KhF85VmYInslhv5tUtMEppfdTLyX4SUKh8ftNIVmH9mXyRCZclSoa6IMd635 Jq1Pj2/Lp64tOzSvN5Y9zaiCc5FucXtB9SaWsgdmFuIFJpZWwgPHJpZWxAc3VycmllbC5jb20+iQE +BBMBAgAoBQJSLd2lAhsjBQkSzAMABgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRDOed6ShMTe g4PpB/0ZivKYFt0LaB22ssWUrBoeNWCP1NY/lkq2QbPhR3agLB7ZXI97PF2z/5QD9Fuy/FD/jddPx KRTvFCtHcEzTOcFjBmf52uqgt3U40H9GM++0IM0yHusd9EzlaWsbp09vsAV2DwdqS69x9RPbvE/Ne fO5subhocH76okcF/aQiQ+oj2j6LJZGBJBVigOHg+4zyzdDgKM+jp0bvDI51KQ4XfxV593OhvkS3z 3FPx0CE7l62WhWrieHyBblqvkTYgJ6dq4bsYpqxxGJOkQ47WpEUx6onH+rImWmPJbSYGhwBzTo0Mm G1Nb1qGPG+mTrSmJjDRxrwf1zjmYqQreWVSFEt26tBpSaWsgdmFuIFJpZWwgPHJpZWxAZmIuY29tP okBPgQTAQIAKAUCW5LbiAIbIwUJEswDAAYLCQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQznneko TE3oOUEQgAsrGxjTC1bGtZyuvyQPcXclap11Ogib6rQywGYu6/Mnkbd6hbyY3wpdyQii/cas2S44N cQj8HkGv91JLVE24/Wt0gITPCH3rLVJJDGQxprHTVDs1t1RAbsbp0XTksZPCNWDGYIBo2aHDwErhI omYQ0Xluo1WBtH/UmHgirHvclsou1Ks9jyTxiPyUKRfae7GNOFiX99+ZlB27P3t8CjtSO831Ij0Ip QrfooZ21YVlUKw0Wy6Ll8EyefyrEYSh8KTm8dQj4O7xxvdg865TLeLpho5PwDRF+/mR3qi8CdGbkE c4pYZQO8UDXUN4S+pe0aTeTqlYw8rRHWF9TnvtpcNzZw== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-1.fc44) MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspam-User: X-Stat-Signature: msggrwxewspg1rdy731n7oew61nzd6hb X-Rspamd-Queue-Id: 693F0C0002 X-HE-Tag: 1789858289-959825 X-HE-Meta: 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 xOLCNVkZ 8JVdY4kWH9ybeInPsd1WVl3Dco7DZzhmdl36mRffituUV/N7AcBJGIit4s2035wk0Bouf0hJbG0dmZFyejxd6oF8WfOxZUCxaTukGAyw5xHQHgrrhCfMzhZFFaAD8U7LHDD/fI0PUWKfwyFAnC5TgSTn8QlAnXFXaTysgnh6rfdV7CoYAUlbV+j99pAFhJx8iGDIQWnGcO2wHX1ATqgTJxuXNjkd8rvyNos7PFhu431kwHgtyIEPhIHnR4dTbnlsjSZCVBuoCwff3qbvI3nJXeUVPjBfZMeS5y2ub3Ps8uU/1unTWPB+phx1s9orIwqcKVzvkAIDMbNrukBpoZnQysm/ybjfQkXV1EiL2zzH/sjK0QL+sU+LZjiBhpsS7SbahAugYnu5y5rJjsHEPr0iT9h6YcSnv1iQly2gu5Q8DNmt1OJSjiAsZFcDhZ8KTThypGJt9foEUubqqmWw= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sat, 2026-09-19 at 11:21 -1000, Chris Li wrote: > On Sat, Sep 19, 2026 at 6:16=E2=80=AFAM Rik van Riel > wrote: > >=20 >=20 > > However, I believe we do need to take care that > > whatever design we go with is actually able to > > support the end user functionality we want. >=20 > Agree. I want to add that we should support new functionality without > sacrificing existing user functionality. >=20 That means things need to work both for users who want to configure a zswap size, and for those who do not. The cgroup memory.swap.max is an existing interface that does that on a per cgroup basis for swap, though in practice the=C2=A0 limit mostly seems to be set to 0 (no swap), or to max (no limit). memory.zswap.max does the same on the zswap side, again mostly 0 or max are used. Are you saying you rely on having something like that at the system level, too? --=20 All Rights Reversed.