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Date:   Thu, 16 Apr 2020 21:41:45 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc:     Andrea Arcangeli <aarcange@redhat.com>, Zi Yan <ziy@nvidia.com>,
        Yang Shi <yang.shi@linux.alibaba.com>,
        Ralph Campbell <rcampbell@nvidia.com>,
        John Hubbard <jhubbard@nvidia.com>,
        William Kucharski <william.kucharski@oracle.com>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv4 4/8] khugepaged: Drain LRU add pagevec after swapin
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On Thu, 16 Apr 2020 19:00:22 +0300 "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> wrote:

> __collapse_huge_page_isolate() may fail due to extra pin in the LRU add
> pagevec. It's pretty common for swapin case: we swap in pages just to
> fail due to the extra pin.
> 
> Drain LRU add pagevec on successful swapin.

I don't see how this patch can do anything to prevent
__collapse_huge_page_isolate() from failing, which is what the
changelog implies.

Can we have a more detailed changelog, please?