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From:   Axel Rasmussen <axelrasmussen@google.com>
Date:   Fri, 7 Jul 2023 10:03:55 -0700
Message-ID: <CAJHvVcj-3gUC3dx4LAVnNr-zgo8+cwjGNafQ480EhDifojrcRA@mail.gmail.com>
Subject: Re: [PATCH v3 7/8] selftests/mm: refactor uffd_poll_thread to allow
 custom fault handlers
To:     Peter Xu <peterx@redhat.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>,
        Brian Geffon <bgeffon@google.com>,
        Christian Brauner <brauner@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Gaosheng Cui <cuigaosheng1@huawei.com>,
        Huang Ying <ying.huang@intel.com>,
        Hugh Dickins <hughd@google.com>,
        James Houghton <jthoughton@google.com>,
        "Jan Alexander Steffens (heftig)" <heftig@archlinux.org>,
        Jiaqi Yan <jiaqiyan@google.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        "Liam R. Howlett" <Liam.Howlett@oracle.com>,
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On Fri, Jul 7, 2023 at 6:42=E2=80=AFAM Peter Xu <peterx@redhat.com> wrote:
>
> On Thu, Jul 06, 2023 at 03:50:35PM -0700, Axel Rasmussen wrote:
> > @@ -247,9 +245,13 @@ static int userfaultfd_stress(void)
> >  {
> >       void *area;
> >       unsigned long nr;
> > -     struct uffd_args args[nr_cpus];
> > +     struct uffd_args *args;
> >       uint64_t mem_size =3D nr_pages * page_size;
> >
> > +     args =3D calloc(nr_cpus, sizeof(struct uffd_args));
> > +     if (!args)
> > +             err("allocating args array failed");
>
> This is trivial, but I think I requested a "free" (or keep it allocate on
> stack) in previous version but it didn't get a response on why we cannot
> and it kept going..  could you help explain?

Oh, sorry! I had meant to change this after our discussion, and simply
overlooked it while reworking the patches.

I'll include this change in a v4 which also addresses e.g. the
comments on commit 1.

>
> --
> Peter Xu
>