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From: Rik van Riel To: Chris Li Cc: Gregory Price , Johannes Weiner , Baoquan He , Nhat Pham , Kairui Song , Michal Hocko , Roman Gushchin , Shakeel Butt , 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 , 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: Mon, 21 Sep 2026 14:52:45 -0400 In-Reply-To: References: <785353ef79844e81a8cd97e87b00ef1f785b15e5.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-Rspam-User: X-Rspamd-Queue-Id: 0247118000B X-Stat-Signature: zhdqucu8nm84bwohoz5i3tnccf4c7dus X-Rspamd-Server: rspam01 X-HE-Tag: 1790016842-904126 X-HE-Meta: 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 xRaKxJjt x10wYrsBKYPcGrz2TcMa+XXTy8OAuxdLweffF4dqwDI00I+ItH4Op4OEO6auXwK7oQPowhr0GXNXoihM+a8C68OiqzO8aslVf2GUGokQkDM0jirfJpkau9bccw3+FnFTBwrUZ7qmi5ZLThn//aebB6spw1/r+n/kPaDASS4tzy14MUjhhfXXv4e4JTjk7HgNBjtzG+kzpMyUa/AP30iQlDz/TRaUpy4PlSMYs8ucZfRx9v64BKg+ZUmyHIl4v1eeNavFLRMP4brZaBs1nrvvvsHGCCfddjb71905ZK+6+l9ArdffoU+/xHr5Job+2vKne4Ht/lw/R/xB7PqlZNbZsJyZjsYLIee9uS3EtXTs5vIh+xKGY5f8CbvNq5XM44ZoOFL3MDr6N7SBDqk+nyVr3dWMyIE61cCTZJU4h7sS6cTVOz0qSi+rng1p7xnkbc9HDdkwkcKf1AdVc7PM= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 2026-09-21 at 08:10 -1000, Chris Li wrote: > On Mon, Sep 21, 2026 at 6:40=E2=80=AFAM Rik van Riel > wrote: > >=20 > > On Mon, 2026-09-21 at 06:31 -1000, Chris Li wrote: > > >=20 > > > Give me some real-world examples of people hitting this kind of > > > limit. > > > e.g. MAX(%)=C2=A0 > 100% and still have a usesable system. I suspect > > > that > > > with 100% zswap usage, the system becomes unusable. Please show > > > me a > > > real world case that proves me wrong. > > >=20 > >=20 > > Here's my desktop system right now. The amount > > of Zswapped is more than twice AnonPages, and > > the system stays perfectly usable. > >=20 > > $ grep -E '(Anon|Zswap|GPU|Swap)' /proc/meminfo > > SwapCached:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 252340 kB > > SwapTotal:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 41523604 kB > > SwapFree:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 9802088 kB > > Zswap:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 8812= 236 kB > > Zswapped:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 24927876 kB > > AnonPages:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 11615760 kB > > AnonHugePages:=C2=A0=C2=A0 1402880 kB > > GPUActive:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 13112428 kB > > GPUReclaim:=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 95980 kB > >=20 > > This is also an example where I cannot really > > predict how much zswap space I need, because > > that depends on what AI model is loaded, > > which drives the GPUActive number, as well > > as the number of browser tabs. > >=20 > > The system is perfectly responsive. >=20 > Great, that is getting somewhere. We are talking about actual usage. > I > really appreciate that. >=20 > May I ask what the total amount of memory (RAM) in your system is? >=20 > I am not asking zswap compare to ANA memory. I want to get the % of > the total RAM. > I assume your desktop has more than 8G of RAM, right? Right now it has 64GB of memory. However, if I were running with 48GB, I would need MORE zswap space, while if I were running with 96GB, I would need less zswap space. How can people be expected to figure out how much zswap space their system will need, when the amount needed to fit a workload does not have a positive correlation with the amount of system memory? --=20 All Rights Reversed.