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Date:   Thu, 18 Feb 2021 14:45:54 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Mike Kravetz <mike.kravetz@oracle.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Zi Yan <ziy@nvidia.com>, Davidlohr Bueso <dbueso@suse.de>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Oscar Salvador <osalvador@suse.de>,
        Joao Martins <joao.m.martins@oracle.com>,
        stable@vger.kernel.org
Subject: Re: [PATCH 1/2] hugetlb: fix update_and_free_page contig page struct
 assumption
Message-ID: <20210218144554.GS2858050@casper.infradead.org>
References: <20210217184926.33567-1-mike.kravetz@oracle.com>
 <20210217110252.185c7f5cd5a87c3f7b0c0144@linux-foundation.org>
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On Wed, Feb 17, 2021 at 11:02:52AM -0800, Andrew Morton wrote:
> On Wed, 17 Feb 2021 10:49:25 -0800 Mike Kravetz <mike.kravetz@oracle.com> wrote:
> > page structs are not guaranteed to be contiguous for gigantic pages.  The
>
> June 2014.  That's a long lurk time for a bug.  I wonder if some later
> commit revealed it.

I would suggest that gigantic pages have not seen much use.  Certainly
performance with Intel CPUs on benchmarks that I've been involved with
showed lower performance with 1GB pages than with 2MB pages until quite
recently.