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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Naoya Horiguchi , Wei Yang , Balbir Singh , , References: <20251122025529.1562592-1-ziy@nvidia.com> <20251122025529.1562592-3-ziy@nvidia.com> <33A929D1-7438-43C1-AA4A-398183976F8F@nvidia.com> <34bafd06-250a-4019-8b34-5ddeedea1cb3@kernel.org> <66C159D8-D267-4B3B-9384-1CE94533990E@nvidia.com> From: Miaohe Lin Message-ID: <6cce0756-cfe1-7b39-d81a-ba1b2cb32fb5@huawei.com> Date: Tue, 25 Nov 2025 17:10:18 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <66C159D8-D267-4B3B-9384-1CE94533990E@nvidia.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.173.125.37] X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To kwepemq500010.china.huawei.com (7.202.194.235) X-Rspamd-Queue-Id: 0196AA0012 X-Rspamd-Server: rspam07 X-Stat-Signature: 9t9qpwd5dtsynpi5a5icrtrt8rrtjwn5 X-Rspam-User: X-HE-Tag: 1764061825-57365 X-HE-Meta: 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 t4h2uE39 ww6GIkbsqQXO1nZr8Qe9pZsNkzFCrKAbTq5Xq1e7z2PAyDnhhTkmFqB5SIduTEjq7DPkGPPajh9vNeiCTMrlfKdFBiAd4rgiDo/xV2QKKarVP0VdMCxkYMHsk/TroUmem4Eq7EXy/NSI/TB48DaqCMi1eMcS4RmM8Fypxu/JpA799/M319zEiOQUDtamQqC4IHyc/dMpJs9IdpROlJYqniSFI1HrqCcQKGTCVJobPwAxVsrJowi/GTZbkKWzPwdxJAmXS8l81DujjHRX6Uyk9/PfJ47RB4jKtt9BlxHD7CugFrZ+jkeSLKPUzpULkvjhBkvI77cKV9V6OvF0HU4L6ZrLu5C81R1T8zXlQehWDIcG5N0NjbXfQDh+uJRSjmBsYW/SPlktqENTOckjdwjKud/CdqPOJU5I1AGPvSRWrqPFMt8c= 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: On 2025/11/25 5:08, Zi Yan wrote: > On 24 Nov 2025, at 14:22, David Hildenbrand (Red Hat) wrote: > > > BTW, this page flag reuse is really confusing. I see PG_checked is > PG_owner_priv_1 too and __folio_migrate_mapping() uses folio_test_swapcache() > to decide the number of i_pages entries. Wouldn’t that cause any issue? > ext4 does not release_folio() for migration when PG_checked is set, > ubifs clears PG_checked in release_folio(). I have not checked all other FS > yet. Maybe later. folio_test_swapbacked() is also checked in folio_test_swapcache: static __always_inline bool folio_test_swapcache(struct folio *folio) { return folio_test_swapbacked(folio) && test_bit(PG_swapcache, folio_flags(folio, 0)); } So IMHO the reuse of this page flag should work fine. Thanks. .