lkml.org 
[lkml]   [2023]   [Oct]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH v3 2/3] userfaultfd: UFFDIO_MOVE uABI
    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
    >

    \
     
     \ /
      Last update: 2023-10-23 19:35    [W:2.837 / U:0.084 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site