From: Peter Xu <peterx@redhat.com>
To: Suren Baghdasaryan <surenb@google.com>
Cc: akpm@linux-foundation.org, viro@zeniv.linux.org.uk,
brauner@kernel.org, shuah@kernel.org, aarcange@redhat.com,
lokeshgidra@google.com, david@redhat.com, hughd@google.com,
mhocko@suse.com, axelrasmussen@google.com, rppt@kernel.org,
willy@infradead.org, Liam.Howlett@oracle.com, jannh@google.com,
zhangpeng362@huawei.com, bgeffon@google.com,
kaleshsingh@google.com, ngeoffray@google.com, jdduke@google.com,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
kernel-team@android.com
Subject: Re: [PATCH v3 2/3] userfaultfd: UFFDIO_MOVE uABI
Date: Mon, 23 Oct 2023 14:37:23 -0400 [thread overview]
Message-ID: <ZTa9Y++/PCV7HRoM@x1n> (raw)
In-Reply-To: <CAJuCfpEDEXHVNYRaPsD3GVbcbZ-NuH0n3Cz-V0MDMhiJG_Esrg@mail.gmail.com>
On Mon, Oct 23, 2023 at 10:43:49AM -0700, Suren Baghdasaryan wrote:
> > Maybe we should follow what it does with mremap()? Then your current code
> > is fine. Maybe that's the better start.
>
> I think that was the original intention, basically treating remapping
> as a write operation. Maybe I should add a comment here to make it
> more clear?
Please avoid mention "emulate as a write" - this is not a write, e.g., we
move a swap entry over without faulting in the page. We also keep the page
states, e.g. on hotness. A write will change all of that.
Now rethinking with the recently merged WP_ASYNC: we ignore uffd-wp, which
means dirty from uffd-wp async tracking POV, that matches with soft-dirty
always set. Looks all good.
Perhaps something like "Follow mremap() behavior; ignore uffd-wp for now"
should work?
--
Peter Xu
next prev parent reply other threads:[~2023-10-23 18:38 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-09 6:42 [PATCH v3 0/3] userfaultfd move option Suren Baghdasaryan
2023-10-09 6:42 ` [PATCH v3 1/3] mm/rmap: support move to different root anon_vma in folio_move_anon_rmap() Suren Baghdasaryan
2023-10-12 22:01 ` Peter Xu
2023-10-13 8:04 ` David Hildenbrand
2023-10-19 15:19 ` Suren Baghdasaryan
2023-10-09 6:42 ` [PATCH v3 2/3] userfaultfd: UFFDIO_MOVE uABI Suren Baghdasaryan
2023-10-09 14:38 ` David Hildenbrand
2023-10-09 16:21 ` Suren Baghdasaryan
2023-10-09 16:23 ` David Hildenbrand
2023-10-09 16:29 ` Lokesh Gidra
2023-10-09 17:56 ` Lokesh Gidra
2023-10-10 1:49 ` Suren Baghdasaryan
2023-10-12 20:11 ` Peter Xu
2023-10-13 9:56 ` David Hildenbrand
2023-10-13 16:08 ` Peter Xu
2023-10-13 16:49 ` Lokesh Gidra
2023-10-13 17:05 ` Peter Xu
2023-10-16 18:01 ` David Hildenbrand
2023-10-16 19:01 ` Peter Xu
2023-10-17 15:55 ` David Hildenbrand
2023-10-17 18:59 ` Peter Xu
2023-10-19 15:41 ` David Hildenbrand
2023-10-19 19:53 ` Peter Xu
2023-10-19 20:02 ` Suren Baghdasaryan
2023-10-19 20:43 ` Peter Xu
2023-10-20 10:02 ` David Hildenbrand
2023-10-20 14:09 ` Suren Baghdasaryan
2023-10-20 17:16 ` David Hildenbrand
2023-10-22 15:46 ` Peter Xu
2023-10-23 12:03 ` David Hildenbrand
2023-10-23 16:36 ` David Hildenbrand
2023-10-23 17:33 ` Suren Baghdasaryan
2023-10-19 21:45 ` Suren Baghdasaryan
2023-10-12 21:59 ` Peter Xu
2023-10-19 21:24 ` Suren Baghdasaryan
2023-10-22 17:01 ` Peter Xu
2023-10-23 17:43 ` Suren Baghdasaryan
2023-10-23 18:37 ` Peter Xu [this message]
2023-10-23 19:01 ` Suren Baghdasaryan
2023-10-17 19:39 ` kernel test robot
2023-10-19 21:55 ` Suren Baghdasaryan
2023-10-23 12:29 ` David Hildenbrand
2023-10-23 15:53 ` David Hildenbrand
2023-10-23 19:00 ` Suren Baghdasaryan
2023-10-23 18:56 ` Suren Baghdasaryan
2023-10-24 14:27 ` David Hildenbrand
2023-10-24 14:36 ` Suren Baghdasaryan
2023-10-09 6:42 ` [PATCH v3 3/3] selftests/mm: add UFFDIO_MOVE ioctl test Suren Baghdasaryan
2023-10-12 22:29 ` Peter Xu
2023-10-19 15:43 ` Suren Baghdasaryan
2023-10-19 17:29 ` Axel Rasmussen
2023-10-19 19:33 ` Peter Xu
-- strict thread matches above, loose matches on Subject: below --
2023-10-19 0:21 [PATCH v3 2/3] userfaultfd: UFFDIO_MOVE uABI kernel test robot
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