linux-kernel - Re: [PATCH v4 5/5] selftests/mm: add UFFDIO

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAJuCfpHzEn0=6-4sngq8qQ6h5mSM+Gj-4OqOGF=cvefouk1cbw@mail.gmail.com>
Date:   Mon, 30 Oct 2023 14:22:15 -0700
From:   Suren Baghdasaryan <surenb@...gle.com>
To:     Peter Xu <peterx@...hat.com>
Cc:     akpm@...ux-foundation.org, viro@...iv.linux.org.uk,
        brauner@...nel.org, shuah@...nel.org, aarcange@...hat.com,
        lokeshgidra@...gle.com, david@...hat.com, hughd@...gle.com,
        mhocko@...e.com, axelrasmussen@...gle.com, rppt@...nel.org,
        willy@...radead.org, Liam.Howlett@...cle.com, jannh@...gle.com,
        zhangpeng362@...wei.com, bgeffon@...gle.com,
        kaleshsingh@...gle.com, ngeoffray@...gle.com, jdduke@...gle.com,
        linux-mm@...ck.org, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org,
        kernel-team@...roid.com
Subject: Re: [PATCH v4 5/5] selftests/mm: add UFFDIO_MOVE ioctl test

On Mon, Oct 30, 2023 at 1:35 PM Peter Xu <peterx@...hat.com> wrote:
>
> On Mon, Oct 30, 2023 at 01:22:02PM -0700, Suren Baghdasaryan wrote:
> > > > +static int adjust_page_size(void)
> > > > +{
> > > > +     page_size = default_huge_page_size();
> > >
> > > This is hacky too, currently page_size is the real page_size backing the
> > > memory.
> > >
> > > To make thp test simple, maybe just add one more test to MOVE a large chunk
> > > to replace the thp test, which may contain a few thps?  It also doesn't
> > > need to be fault based.
> >
> > Sorry, I didn't get your suggestion. Could you please clarify? Which
> > thp test are you referring to?
>
> The new "move-pmd" test.
>
> I meant maybe it makes sense to have one separate MOVE test for when one
> ioctl(MOVE) covers a large range which can cover some thps.  Then that will
> trigger thp paths.  Assuming the fault paths are already covered in the
> generic "move" test.

Oh, you mean I should not share uffd_move_test() between move and
move-pmd test and have separate logic instead that does not rely on
the page_size overrides? If so then I think that's doable. Some more
code but probably cleaner.

>
> Thanks,
>
> --
> Peter Xu
>