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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Mon, 22 May 2023 11:48:52 -0700
Message-ID: <CAHk-=wg+PHQ9PhTeQOb7Fh5Qf3zkzG5J1h3D=eOY-2AsYXhU4Q@mail.gmail.com>
Subject: Re: [patch] mm, debug: allow suppressing panic on CONFIG_DEBUG_VM checks
To:     David Rientjes <rientjes@google.com>
Cc:     David Hildenbrand <david@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@kernel.org>, Alex Shi <alexs@kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Matthew Wilcox <willy@infradead.org>,
        Alexander Duyck <alexanderduyck@fb.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
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On Mon, May 22, 2023 at 11:39=E2=80=AFAM David Rientjes <rientjes@google.co=
m> wrote:
>
> I think VM_BUG_ON*() and friends are used to crash the kernel for
> debugging so that we get a crash dump and because some variants don't
> exist for VM_WARN_ON().

I do think that from a VM developer standpoint, I think it should be
fine to just effectively turn VM_BUG_ON() into WARN_ON_ONCE() together
with panic_on_warn.

Maybe we could even extend 'panic_on_warn' to be a bitmap and
effectively have a "don't panic on non-VM warnings" option.

                Linus