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Perez de Azpillaga" , Johannes Weiner Cc: Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Zi Yan , David Hildenbrand , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , JP Kobryn , Frank van der Linden , Thadeu Lima de Souza Cascardo , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20261109-kswapd-highatomic-unreserve-v2-1-6587ca75c77f@kernel.org> <057dc7a4-cdf6-48dd-b326-49c92a936b9b@gmail.com> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSNWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBrZXJuZWwub3JnPsLBsAQTAQoAWhYhBKlA1DSZLC6OmRA9UCJPp+fM gqZkBQJqFFy6GxSAAAAAAAQADm1hbnUyLDIuNSsxLjEyLDIsMgIbAwUJGtCBUAULCQgHAwUV CgkICwUWAgMBAAIeBQIXgAAKCRAiT6fnzIKmZJIUEADFx/tREzUImHrEwVHeSvDFmA7tJysI UVrlvrM09E7GIuzphzv7jYmo8n3ANpCczLEVr4G0syYQdTigaZgv3+FQDIIzhKih1IHhu1Ei XHlywNWKnQxxQEUNi5Mwx43wQz5XVw9F1A7gtKBKNtfogO511hAbrzagrYajyQacEJ/+sfhZ 9Da8ltHIXD8pcYaHUfQgEusCgmEd9+KrUwrTbckFKmYq5chuE6yJ4J0EmWknL096jIE6CnzF FRslQ3B1UKDjxVsm1ZHfir5NeWszLkTvGFsddFaWTgh8UycESG6VQzKXjjewXu2pG7YQYRpj QKm1W5X2TkwWkXRBZTmfmbhxIUMh3+zf5wQ463rSmDN/8v81tdqBtAW6rH/kzg1GvkaTHXn0 507yEHFzBksk2viAuIxxr7km8+/KARYLIdGtx30EG8cKzAUZOK6WqxtNCsXUJNrVE8CWrCaD icoNu7Fs1c5hmPHdSTnU48ce67449DdnO4neLSNhRiGlMHJgfJUmgrxu/hcYeOZ3haWmEQ2w uW1Mh01OHi8QZHCEyAbABrPs9GUgccc/4eYXX9hIgxfSkYzn8f+8NuIFPWl/0uTvjgqU29FQ SbzOLxHq9439Ox40G5mS5eZXRGxITYR+6TXvRGI6P/264jvflnr/pDGUttaikU+0W+1uxgKH cmYbEc7ATQRbGTU1AQgAn0H6UrFiWcovkh6EXVcl+SeqyO6JHOPm+e9Wu0Vw+VIUvXZVUVVQ La1PQDUi6j00ChlcR66g9/V0sPIcSutacPKfdKYOBvzd4rlhL8rfrdEsQw5ApZxrA8kYZVMh FmBRKAa6wos25moTlMKpCWzTH84+WO5+ziCTsTUZASAToz3RdunTD+vQcHj0GqNTPAHK63sf bAB2I0BslZkXkY1RLb/YhuA6E7JyEd2pilZOrIuBGl/5q2qSakgnAVFWFBR/DO27JuAksYnq +aH8vI0xGvwn75KqSk4UzAkDzWSmO4ZHuahKtQgZNsMYV+PGayRBX9b9zbldzopoLBdqHc4n jQARAQABwsF8BBgBCgAmAhsMFiEEqUDUNJksLo6ZED1QIk+n58yCpmQFAmfIHFQFCRYU6J8A CgkQIk+n58yCpmS2PA//bqN1LfcotmArgElsa+0EGZSQlYgK48pm8WAeTXTngudP9IJ4SuKY HR5RNjHcBeqN+Me0zxRqYzRb8nGanHEkDyf4Im8DQM8d6vbyU+FcPmG4skud4kgS1zMHnlVd SXfSIwKC/hKgdHG8aBV7545Lz9X6Iohea+94wneD0aw/hqF+QWewGZhWJriWAZtvEkzNjQOi 4U9F/trLten/x7bpphDSnDMKJtITbtzATT1Dq7o7VpIUK1nCTQALMuMjKCdi8OdU/+V+R3O4 0PXWvX8qrvqYapVbZ+9KqT74FsuB0Ya9uXwgBF2Q6cRuETZk5vqaqKxzqoQZCO8AOz/58j6O 2RHNy/mZEN+7tJ5Tsq42zVJ4jxsT8b9YplavCMsnBgDeRWhcbYhCyttoL7nYISyWg4kQYZ/P wIV3OuNv2f8iKYsxNsRuClOAF82+gvqOy1/1pprFjy8uo2pkoOrb63aOP3vO5VHnRKgra6dq NcaZ+c6J4H+nEJGi2SkHAUJz5oBzuThvPudLvPA/SK8sKoM01IRxSihev/S/5WLazXB1PGem OCbvzC1IjWJJraxiDJ5IygokapUa2RP7+WBR22skQ3SSl6G107QgWKSyTOGWEaRmV53vxQLV jXuCmzSSasTL60zq5yGrT4/DYQVSNEUiUbG4pYekxJujNeEDkUlky0Y= In-Reply-To: <057dc7a4-cdf6-48dd-b326-49c92a936b9b@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Rspamd-Server: rspam09 X-Stat-Signature: wfye9gak93kbagqaqdb338qa6jexgojh X-Rspamd-Queue-Id: C8B4A140005 X-Rspam-User: X-HE-Tag: 1794392574-297597 X-HE-Meta: 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 w4m1Oimb QWAYI34jETTX0JRaIE3nemLxvVfiHH0WovYnfC+hn5ouzfu4bDdwFUr4KhhuEaTdrj8WpfZ6xJGv7SWceW9ul/kWApdCrdSbA9y9R5UTpvaxbsz5Vtk7h/aKfxlIhnE8/UOR+KdZI144BrG4ffXVQp84rNhL2Xt1VPpIBccs2lYplf811CUUvnJL8QZwTnBmURj5rMBQ8iPmDr6zdsgSULG20LBqFC6R/T/wndtXLkH6IST+AkYOuTidFvzgcV1Ani8aUdRO9tGpus87+fDeohaFWyl5CwOp4pAys3HCnbA183QK9wML8V8KdwDpAmwQlpyI7AvQQ6tCtdxDJZ2ha2T27/Q== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 11/10/26 14:25, Jose A. Perez de Azpillaga wrote: > On 11/9/26 11:20 AM, Vlastimil Babka (SUSE) wrote: > [snip] > >> Hook this highatomic unreserve to the moment we exit the loop in >> balance_pgdat() due to exhausting reclaim priority, which means pgdat >> was not balanced and the last kswapd_shrink_node() attempt returned >> false or failed to reclaim anything. Even if that last attempt made the >> pgdat balanced, kswapd was struggling enough, so unreserving is far from >> premature. This should be a more conservative variant of when direct >> reclaim failure triggers the unreserving. Pass force as true to make >> sure repeated failures fully unreserve everything. Also make sure we >> don't count kswapd failures until then. Don't restart immediately as >> the kswapd() loop will call balance_pgdat() again if the unreserve does >> not lead to a balanced pgdat. >> > > the lowest priority gating looks good to me. > > however, sashiko found some concerns [1]. Yeah I saw, and I wonder why there was no email this time. The inability to unreserve when there's no free highatomic pages to grab onto is concerning on its own. Should be a pfn scanner probably. > [1]: > https://sashiko.dev/#/patchset/20261109-kswapd-highatomic-unreserve-v2-1-6587ca75c77f%40kernel.org >