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References: <20230721225107.942336-1-jannh@google.com> <20230724101136.4c58e8291961e87f6c5c1c79@linux-foundation.org>
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From:   Jann Horn <jannh@google.com>
Date:   Mon, 24 Jul 2023 19:29:09 +0200
Message-ID: <CAG48ez1RPZQ0p7dB3BsVwiTPHqge1Ja7E-XCQp-P7xBHT+AM=w@mail.gmail.com>
Subject: Re: [PATCH v2] mm: Fix memory ordering for mm_lock_seq and vm_lock_seq
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Suren Baghdasaryan <surenb@google.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Hugh Dickins <hughd@google.com>
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On Mon, Jul 24, 2023 at 7:11=E2=80=AFPM Andrew Morton <akpm@linux-foundatio=
n.org> wrote:
> On Sat, 22 Jul 2023 00:51:07 +0200 Jann Horn <jannh@google.com> wrote:
> > BACKPORT WARNING: One of the functions changed by this patch (which I'v=
e
> > written against Linus' tree) is vma_try_start_write(), but this functio=
n
> > no longer exists in mm/mm-everything. I don't know whether the merged
> > version of this patch will be ordered before or after the patch that
> > removes vma_try_start_write(). If you're backporting this patch to a
> > tree with vma_try_start_write(), make sure this patch changes that
> > function.
>
> I staged this patch as a hotfix, ahead of mm-unstable material.
>
> The conflict is with Hugh's "mm: delete mmap_write_trylock() and
> vma_try_start_write()"
> (https://lkml.kernel.org/r/4e6db3d-e8e-73fb-1f2a-8de2dab2a87c@google.com)
>
> I fixed the reject in the obvious way (deleted the function anyway),
> but there's a possibility that the ordering issue you have addressed
> will now be reintroduced by Hugh's series, so please let's review that.

Thanks. I've looked at Hugh's series and what you did (deleting the
function anyway) looks good to me.