Messages in this thread | | | Date | Mon, 20 Nov 2023 00:26:24 -0800 | From | Christoph Hellwig <> | Subject | Re: [PATCH RFC 06/12] mm/gup: Drop folio_fast_pin_allowed() in hugepd processing |
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On Wed, Nov 15, 2023 at 08:29:02PM -0500, Peter Xu wrote: > Hugepd format is only used in PowerPC with hugetlbfs. In commit > a6e79df92e4a ("mm/gup: disallow FOLL_LONGTERM GUP-fast writing to > file-backed mappings"), we added a check to fail gup-fast if there's > potential risk of violating GUP over writeback file systems. That should > never apply to hugepd. > > Drop that check, not only because it'll never be true for hugepd, but also > it paves way for reusing the function outside fast-gup.
What prevents us from ever using hugepd with file mappings? I think it would naturally fit in with how large folios for the pagecache work.
So keeping this check and generalizing it seems like the better idea to me.
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