Messages in this thread | | | Date | Mon, 23 Oct 2023 18:36:16 +0200 | Subject | Re: [PATCH v3 2/3] userfaultfd: UFFDIO_MOVE uABI | From | David Hildenbrand <> |
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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]
-- Cheers,
David / dhildenb
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