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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: 31D6D140006 X-Rspamd-Server: rspam06 X-Stat-Signature: kscfwwaq5g7c1eyr7185z171z6swoygy X-HE-Tag: 1752767661-435158 X-HE-Meta: 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 rwnhfj6d 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 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 2025-07-16 21:52, Luiz Capitulino wrote: > On 2025-07-16 18:19, Andrew Morton wrote: >> On Wed, 16 Jul 2025 20:18:00 +0200 David Hildenbrand wrote: >> >>> On 16.07.25 19:36, Luiz Capitulino wrote: >>>> Yes, good catch. This was from an earlier version. >>>> >>>> Is it fine if I fix only this with a follow up patch for Andrew in this >>>> thread or would you prefer that I post v4 with all the other changes as >>>> well? >>> >>> I think the series was part of mm-new, but now I only spot it in >>> mm-everything, weird. Maybe because of a conflict with the other >>> stable_page_flags() change? >> >> I think I removed v2 from mm-unstable and added v3 to mm-new. Maybe. >> >>> So whatever Andrew prefers, really :) >> >> Either is OK at this stage. I do prefer little fixes so that I and >> others can see what changed - it depends how tricky and large they are. > > I liked some of the other suggestions from David so I'll send v4. I changed my mind again (sorry). I think the current version should be good as is except for the doc bug, so here's a patch to fix it on top: diff --git a/mm/util.c b/mm/util.c index f270bf42465b..6e5b6ff1c90d 100644 --- a/mm/util.c +++ b/mm/util.c @@ -1198,10 +1198,12 @@ static void set_ps_flags(struct page_snapshot *ps, const struct folio *folio, * Create a snapshot of the page and store both its struct page and struct * folio representations in @ps. * - * Note that creating a faithful snapshot may fail if the compound - * state of the page keeps changing (e.g., due to a folio split). In - * this case, ps->faithful is set to false, and the snapshot assumes - * that @page refers to a single page. + * A snapshot is marked as "faithful" if the compound state of @page was + * stable and allowed safe reconstruction of the folio representation. In + * rare cases where this is not possible (e.g. due to folio splitting), + * snapshot_page() falls back to treating @page as a single page and the + * snapshot is marked as "unfaithful". The snapshot_page_is_faithful() + * helper can be used to check for this condition. */ void snapshot_page(struct page_snapshot *ps, const struct page *page) {