From: Christoph Hellwig <hch@infradead.org>
To: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
James Houghton <jthoughton@google.com>,
Lorenzo Stoakes <lstoakes@gmail.com>,
David Hildenbrand <david@redhat.com>,
John Hubbard <jhubbard@nvidia.com>,
Yang Shi <shy828301@gmail.com>, Rik van Riel <riel@surriel.com>,
Hugh Dickins <hughd@google.com>,
linux-kernel@vger.kernel.org,
Matthew Wilcox <willy@infradead.org>,
linux-mm@kvack.org, Mike Rapoport <rppt@kernel.org>,
Jason Gunthorpe <jgg@nvidia.com>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Axel Rasmussen <axelrasmussen@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
linuxppc-dev@lists.ozlabs.org, Vlastimil Babka <vbabka@suse.cz>,
Mike Kravetz <mike.kravetz@oracle.com>
Subject: Re: [PATCH RFC 06/12] mm/gup: Drop folio_fast_pin_allowed() in hugepd processing
Date: Mon, 20 Nov 2023 00:26:24 -0800 [thread overview]
Message-ID: <ZVsYMMJpmFV2T/Zc@infradead.org> (raw)
In-Reply-To: <20231116012908.392077-7-peterx@redhat.com>
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.
next prev parent reply other threads:[~2023-11-20 8:27 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20231116012908.392077-1-peterx@redhat.com>
2023-11-16 1:29 ` [PATCH RFC 06/12] mm/gup: Drop folio_fast_pin_allowed() in hugepd processing Peter Xu
2023-11-20 8:26 ` Christoph Hellwig [this message]
2023-11-21 15:59 ` Peter Xu
2023-11-22 8:00 ` Christoph Hellwig
2023-11-22 15:22 ` Peter Xu
2023-11-23 7:21 ` Christoph Hellwig
2023-11-23 16:10 ` Peter Xu
2023-11-23 18:22 ` Christophe Leroy
2023-11-23 19:37 ` Peter Xu
2023-11-24 5:28 ` Aneesh Kumar K.V
2023-11-24 7:03 ` Christophe Leroy
2023-11-24 18:16 ` Peter Xu
2023-11-24 1:06 ` Michael Ellerman
2023-11-23 15:47 ` Matthew Wilcox
2023-11-23 17:22 ` Peter Xu
2023-11-23 19:11 ` Ryan Roberts
2023-11-23 19:46 ` Peter Xu
2023-11-24 9:06 ` Ryan Roberts
2023-11-24 16:07 ` Peter Xu
2023-11-30 21:30 ` Peter Xu
2023-12-03 13:33 ` Christophe Leroy
2023-12-04 11:11 ` Ryan Roberts
2023-12-04 11:25 ` Christophe Leroy
2023-12-04 11:46 ` Ryan Roberts
2023-12-04 11:57 ` Christophe Leroy
2023-12-04 12:02 ` Ryan Roberts
2023-12-04 16:48 ` Peter Xu
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