From: Suren Baghdasaryan <surenb@google.com>
To: David Hildenbrand <david@redhat.com>
Cc: Peter Xu <peterx@redhat.com>,
Lokesh Gidra <lokeshgidra@google.com>,
akpm@linux-foundation.org, viro@zeniv.linux.org.uk,
brauner@kernel.org, shuah@kernel.org, aarcange@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 10:33:40 -0700 [thread overview]
Message-ID: <CAJuCfpF+ADAG=vn4y0EKo29j5zUx-TG=puF7Bq8oSp1_7T+OSw@mail.gmail.com> (raw)
In-Reply-To: <96899aa6-700b-41b9-ab11-2cae48d75549@redhat.com>
On Mon, Oct 23, 2023 at 9:36 AM David Hildenbrand <david@redhat.com> wrote:
>
> On 23.10.23 14:03, David Hildenbrand wrote:
> > On 22.10.23 17:46, Peter Xu wrote:
> >> On Fri, Oct 20, 2023 at 07:16:19PM +0200, David Hildenbrand wrote:
> >>> These are rather the vibes I'm getting from Peter. "Why rename it, could
> >>> confuse people because the original patches are old", "Why exclude it if it
> >>> has been included in the original patches". Not the kind of reasoning I can
> >>> relate to when it comes to upstreaming some patches.
> >>
> >> You can't blame anyone if you misunderstood and biased the question.
> >>
> >> The first question is definitely valid, even until now. You guys still
> >> prefer to rename it, which I'm totally fine with.
> >>
> >> The 2nd question is wrong from your interpretation. That's not my point,
> >> at least not starting from a few replies already. What I was asking for is
> >> why such page movement between mm is dangerous. I don't think I get solid
> >> answers even until now.
> >>
> >> Noticing "memcg is missing" is not an argument for "cross-mm is dangerous",
> >> it's a review comment. Suren can address that.
> >>
> >> You'll propose a new feature that may tag an mm is not an argument either,
> >> if it's not merged yet. We can also address that depending on what it is,
> >> also on which lands earlier.
> >>
> >> It'll be good to discuss these details even in a single-mm support. Anyone
> >> would like to add that can already refer to discussion in this thread.
> >>
> >> I hope I'm clear.
> >>
> >
> > I said everything I had to say, go read what I wrote.
>
> Re-read your message after flying over first couple of paragraphs
> previously a bit quick too quickly (can easily happen when I'm told that
> I misunderstand questions and read them in a "biased" way).
>
> I'll happy to discuss cross-mm support once we actually need it. I just
> don't see the need to spend any energy on that right now, without any
> users on the horizon.
>
> [(a) I didn't blame anybody, I said that I don't understand the
> reasoning. (b) I hope I made it clear that this is added complexity (and
> not just currently dangerous) and so far I haven't heard a compelling
> argument why we should do any of that or even spend our time discussing
> that. (c) I never used "memcg is missing" as an argument for "cross-mm
> is dangerous", all about added complexity without actual users. (d) "it
> easily shows that there are cases where this will require extra work --
> without any current benefits" -- is IMHO a perfectly fine argument
> against complexity that currently nobody needs]
Thanks for the discussion, folks!
I think posting the single-mm first and then following up with
cross-mm and its test would help us move forward. That will provide
functionality that is needed today quickly without unnecessary
distractions and will give us more time to discuss cross-mm support.
Also we will be able to test single-mm in isolation and make it more
solid before moving onto cross-mm.
I'll try to post the next version sometime this week.
Thanks,
Suren.
>
> --
> Cheers,
>
> David / dhildenb
>
next prev parent reply other threads:[~2023-10-23 17:33 UTC|newest]
Thread overview: 52+ 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 [this message]
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
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
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='CAJuCfpF+ADAG=vn4y0EKo29j5zUx-TG=puF7Bq8oSp1_7T+OSw@mail.gmail.com' \
--to=surenb@google.com \
--cc=Liam.Howlett@oracle.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=axelrasmussen@google.com \
--cc=bgeffon@google.com \
--cc=brauner@kernel.org \
--cc=david@redhat.com \
--cc=hughd@google.com \
--cc=jannh@google.com \
--cc=jdduke@google.com \
--cc=kaleshsingh@google.com \
--cc=kernel-team@android.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=lokeshgidra@google.com \
--cc=mhocko@suse.com \
--cc=ngeoffray@google.com \
--cc=peterx@redhat.com \
--cc=rppt@kernel.org \
--cc=shuah@kernel.org \
--cc=viro@zeniv.linux.org.uk \
--cc=willy@infradead.org \
--cc=zhangpeng362@huawei.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).