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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sat, 7 Sep 2019 12:55:36 -0700
Message-ID: <CAHk-=wifuQ68e6Q4F2txGS48WgcoX2REE4te5_j36ypV-T2ZKw@mail.gmail.com>
Subject: Re: [patch for-5.3 0/4] revert immediate fallback to remote hugepages
To:     David Rientjes <rientjes@google.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Michal Hocko <mhocko@suse.com>, Mel Gorman <mgorman@suse.de>,
        Vlastimil Babka <vbabka@suse.cz>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
        Linux-MM <linux-mm@kvack.org>
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On Sat, Sep 7, 2019 at 12:51 PM David Rientjes <rientjes@google.com> wrote:
>
> Andrea acknowledges the swap storm that he reported would be fixed with
> the last two patches in this series

The problem is that even you aren't arguing that those patches should
go into 5.3.

So those fixes aren't going in, so "the swap storms would be fixed"
argument isn't actually an argument at all as far as 5.3 is concerned.

End result: we'd have the qemu-kvm instance performance problem in 5.3
that apparently causes distros to apply those patches that you want to
revert anyway.

So reverting would just make distros not use 5.3 in that form.

So I don't think we can revert those again without applying the two
patches in the series. So it would be a 5.4 merge window operation.

               Linus