From: Rik van Riel <riel@surriel.com>
To: John Hubbard <jhubbard@nvidia.com>,
"David Hildenbrand (Arm)" <david@kernel.org>,
linux-kernel@vger.kernel.org
Cc: kernel-team@meta.com, Andrew Morton <akpm@linux-foundation.org>,
Jason Gunthorpe <jgg@ziepe.ca>, Peter Xu <peterx@redhat.com>,
linux-mm@kvack.org
Subject: Re: [RFC PATCH v3 3/8] mm/gup: split follow_page_pte_commit() out of follow_page_pte()
Date: Sat, 22 Aug 2026 09:20:07 -0400 [thread overview]
Message-ID: <f86ca125a9b63cdab8edeb3c3b02a29141f18c1a.camel@surriel.com> (raw)
In-Reply-To: <fe9f0bb5-73e3-4509-951d-e529e37011fd@nvidia.com>
On Fri, 2026-08-21 at 15:04 -0700, John Hubbard wrote:
>
> You have delved too deep, and now uncovered something that's been
> a problem for the whole time. :)
>
> Specifically, "no, GUP should not be setting folios nor pages
> dirty", because that generally needs to be done as part of a
> filesystem
> coordinated set of steps. If the page is dirty, and the filesystem
> didn't expect it to be, that leads to problems.
>
> This is part of the big, remaining set of required fixes, that
> launched the creation of pin_user_pages*() and related. Connecting
> up the filesystems properly is yet to be done. And until then, this
> is a real defect.
>
Not just filesystems.
I found about two dozen places where drivers
fail to mark a page dirty after writing to
it, after obtaining the page from GUP.
I'll get out patches for that, unless there's
some reason I shouldn't.
--
All Rights Reversed.
next prev parent reply other threads:[~2026-08-22 13:20 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-11 2:51 [RFC PATCH v3 0/8] batch lookups in follow_page_mask() Rik van Riel
2026-08-11 2:51 ` [RFC PATCH v3 1/8] mm/gup: break out gup_fill_pages() helper Rik van Riel
2026-08-28 21:24 ` Suren Baghdasaryan
2026-08-11 2:51 ` [RFC PATCH v3 2/8] mm/gup: convert follow_page_mask() to return a long Rik van Riel
2026-08-28 21:28 ` Suren Baghdasaryan
2026-08-11 2:51 ` [RFC PATCH v3 3/8] mm/gup: split follow_page_pte_commit() out of follow_page_pte() Rik van Riel
2026-08-12 11:50 ` David Hildenbrand (Arm)
2026-08-12 13:02 ` Rik van Riel
2026-08-12 13:23 ` David Hildenbrand (Arm)
2026-08-12 16:19 ` Rik van Riel
2026-08-21 17:38 ` Rik van Riel
2026-08-21 22:04 ` John Hubbard
2026-08-22 13:20 ` Rik van Riel [this message]
2026-08-22 21:31 ` John Hubbard
2026-08-24 13:20 ` Rik van Riel
2026-08-11 2:51 ` [RFC PATCH v3 4/8] mm/gup: break out follow_one_pte() helper Rik van Riel
2026-08-28 23:47 ` Suren Baghdasaryan
2026-08-29 2:11 ` Rik van Riel
2026-08-11 2:51 ` [RFC PATCH v3 5/8] mm/gup: fill the pages array outside the pud/pmd lock Rik van Riel
2026-08-29 3:00 ` Suren Baghdasaryan
2026-08-11 2:51 ` [RFC PATCH v3 6/8] mm/gup: return a huge page's full count from follow_page_mask() Rik van Riel
2026-08-11 2:51 ` [RFC PATCH v3 7/8] mm/gup: walk multiple PTEs per follow_page_pte() call Rik van Riel
2026-08-29 3:06 ` Suren Baghdasaryan
2026-08-11 2:51 ` [RFC PATCH v3 8/8] mm/gup: batch contiguous same-folio PTEs into one refcount grab Rik van Riel
2026-08-12 11:41 ` [RFC PATCH v3 0/8] batch lookups in follow_page_mask() David Hildenbrand (Arm)
2026-08-25 7:52 ` Christoph Hellwig
2026-08-25 13:37 ` Rik van Riel
2026-08-26 4:39 ` Christoph Hellwig
2026-08-26 7:35 ` Christoph Hellwig
2026-08-26 8:27 ` David Hildenbrand (Arm)
2026-08-26 13:36 ` Rik van Riel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=f86ca125a9b63cdab8edeb3c3b02a29141f18c1a.camel@surriel.com \
--to=riel@surriel.com \
--cc=akpm@linux-foundation.org \
--cc=david@kernel.org \
--cc=jgg@ziepe.ca \
--cc=jhubbard@nvidia.com \
--cc=kernel-team@meta.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=peterx@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.