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b=YB6lzGB9yPROCeUmtjE1/+hDeCZy2joy8cazV0rTfo7VRK8rjoCttdnd2AkrBwN9o 99Xo7Y2Ad0TsI1xQobp79/nc9HAEWI6tQKLBjJA0RU0ukF2JviGhl2FAffbPB9imvD 9WQ9CQ+AXfGiLAArgSmPgePODtTgLJvKgTAmLKQXH7S981Ss81y2bHISN/53w/Cq1r 3m2yKs65Qr9vvt3+lKhMmNxvu49b0E9oDR9mQGcd27uijgLkXh6lO2ppYdG8hqUA0E KHBtHp5ZKhZN2pI5sMo5pCSxkKf+fLkZvF/AhBd92G/5d7+BNCZf3Bw4NZfLZchrQ4 tLTxqgUEQOo4A== Message-ID: <7f053290-6b9a-4d18-936e-0f28006c79c3@kernel.org> Date: Tue, 6 Jan 2026 16:24:21 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH] memory,memory_hotplug: allow restricting memory blocks to zone movable To: Gregory Price , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, osalvador@suse.de, gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, akpm@linux-foundation.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, hare@suse.de References: <20260105203611.4079743-1-gourry@gourry.net> From: "David Hildenbrand (Red Hat)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAa2VybmVsLm9yZz7CwY0EEwEIADcWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCaKYhwAIbAwUJJlgIpAILCQQVCgkIAhYCAh4FAheAAAoJEE3eEPcA/4Naa5EP/3a1 9sgS9m7oiR0uenlj+C6kkIKlpWKRfGH/WvtFaHr/y06TKnWn6cMOZzJQ+8S39GOteyCCGADh 6ceBx1KPf6/AvMktnGETDTqZ0N9roR4/aEPSMt8kHu/GKR3gtPwzfosX2NgqXNmA7ErU4puf zica1DAmTvx44LOYjvBV24JQG99bZ5Bm2gTDjGXV15/X159CpS6Tc2e3KvYfnfRvezD+alhF XIym8OvvGMeo97BCHpX88pHVIfBg2g2JogR6f0PAJtHGYz6M/9YMxyUShJfo0Df1SOMAbU1Q Op0Ij4PlFCC64rovjH38ly0xfRZH37DZs6kP0jOj4QdExdaXcTILKJFIB3wWXWsqLbtJVgjR YhOrPokd6mDA3gAque7481KkpKM4JraOEELg8pF6eRb3KcAwPRekvf/nYVIbOVyT9lXD5mJn IZUY0LwZsFN0YhGhQJ8xronZy0A59faGBMuVnVb3oy2S0fO1y/r53IeUDTF1wCYF+fM5zo14 5L8mE1GsDJ7FNLj5eSDu/qdZIKqzfY0/l0SAUAAt5yYYejKuii4kfTyLDF/j4LyYZD1QzxLC MjQl36IEcmDTMznLf0/JvCHlxTYZsF0OjWWj1ATRMk41/Q+PX07XQlRCRcE13a8neEz3F6we 08oWh2DnC4AXKbP+kuD9ZP6+5+x1H1zEzsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCgh Cj/CA/lc/LMthqQ773gauB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseB fDXHA6m4B3mUTWo13nid0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts 6TZ+IrPOwT1hfB4WNC+X2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiu Qmt3yqrmN63V9wzaPhC+xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKB Tccu2AXJXWAE1Xjh6GOC8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvF FFyAS0Nk1q/7EChPcbRbhJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh 2YmnmLRTro6eZ/qYwWkCu8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRk F3TwgucpyPtcpmQtTkWSgDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0L LH63+BrrHasfJzxKXzqgrW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4v q7oFCPsOgwARAQABwsF8BBgBCAAmAhsMFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAmic2qsF CSZYCKEACgkQTd4Q9wD/g1oq0xAAsAnw/OmsERdtdwRfAMpC74/++2wh9RvVQ0x8xXvoGJwZ rk0Jmck1ABIM//5sWDo7eDHk1uEcc95pbP9XGU6ZgeiQeh06+0vRYILwDk8Q/y06TrTb1n4n 7FRwyskKU1UWnNW86lvWUJuGPABXjrkfL41RJttSJHF3M1C0u2BnM5VnDuPFQKzhRRktBMK4 GkWBvXlsHFhn8Ev0xvPE/G99RAg9ufNAxyq2lSzbUIwrY918KHlziBKwNyLoPn9kgHD3hRBa Yakz87WKUZd17ZnPMZiXriCWZxwPx7zs6cSAqcfcVucmdPiIlyG1K/HIk2LX63T6oO2Libzz 7/0i4+oIpvpK2X6zZ2cu0k2uNcEYm2xAb+xGmqwnPnHX/ac8lJEyzH3lh+pt2slI4VcPNnz+ vzYeBAS1S+VJc1pcJr3l7PRSQ4bv5sObZvezRdqEFB4tUIfSbDdEBCCvvEMBgoisDB8ceYxO cFAM8nBWrEmNU2vvIGJzjJ/NVYYIY0TgOc5bS9wh6jKHL2+chrfDW5neLJjY2x3snF8q7U9G EIbBfNHDlOV8SyhEjtX0DyKxQKioTYPOHcW9gdV5fhSz5tEv+ipqt4kIgWqBgzK8ePtDTqRM qZq457g1/SXSoSQi4jN+gsneqvlTJdzaEu1bJP0iv6ViVf15+qHuY5iojCz8fa0= In-Reply-To: <20260105203611.4079743-1-gourry@gourry.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam02 X-Stat-Signature: 5it3dc4ozih9e77hndpo7wemo8grfa3b X-Rspam-User: X-Rspamd-Queue-Id: 72E72C0009 X-HE-Tag: 1767713068-684653 X-HE-Meta: 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 P/bigrpr lDintuXztSmpm8Roaa/ozUh5VUZ2u/fGuC6TaPG5jKLduDw3YYsD+czNceeYFnxAW9/TXTEhkXI4uEH0BbYrYS51EVirdu3N69ZRttDThfDuhWcmYI4nrjThYxdzg8A3JvuZhqyZM4efKtgrjOnSMGY76M+Ukkz7dFQYuwsUyqGGXVdsPPQxIPjp+dt8SwS7d9tgndJHngUtPGdVRS3Kk9OESWymvgQDqfBWuS60AwbuunIQvJLlK0UgGRlls2nifLXsqG7G/rXUbJVLbA5RMfK+blvFIOwgyXul4+8OZQT+a6arLUiPG2oL/JQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > +/* > + * Restrict hotplugged memory blocks to ZONE_MOVABLE only. > + * > + * During offlining of hotplugged memory which was originally onlined > + * as ZONE_MOVABLE, userland services may detect blocks going offline > + * and automatically re-online them into ZONE_NORMAL or lower. When > + * this happens it may become permanently incapable of being removed. If it's really only that, we could also look into simply making a re-online without a specific mode ("online") to use the previous mode. We could glue that to the "contig-zones" policy only, to not affect "auto-movable". That is, remember the zone to which it was previously onlined, and then simply re-online to that one. -- Cheers David