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References: <20220318111709.60311-1-linmiaohe@huawei.com> <20220318111709.60311-10-linmiaohe@huawei.com>
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From:   Muchun Song <songmuchun@bytedance.com>
Date:   Fri, 18 Mar 2022 16:24:48 +0800
Message-ID: <CAMZfGtXbU5EzVD8SH3S0vvTvzzHN7UE6qJ51KU9P5n_KC8JLJA@mail.gmail.com>
Subject: Re: [PATCH v2 09/11] mm/migration: fix potential page refcounts leak
 in migrate_pages
To:     Miaohe Lin <linmiaohe@huawei.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>, Zi Yan <ziy@nvidia.com>,
        baolin.wang@linux.alibaba.com, Huang Ying <ying.huang@intel.com>,
        Alistair Popple <apopple@nvidia.com>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Thu, Mar 17, 2022 at 10:41 PM Miaohe Lin <linmiaohe@huawei.com> wrote:
>
> In -ENOMEM case, there might be some subpages of fail-to-migrate THPs
> left in thp_split_pages list. We should move them back to migration
> list so that they could be put back to the right list by the caller
> otherwise the page refcnt will be leaked here. Also adjust nr_failed
> and nr_thp_failed accordingly to make vm events account more accurate.
>
> Fixes: b5bade978e9b ("mm: migrate: fix the return value of migrate_pages()")
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> Reviewed-by: Zi Yan <ziy@nvidia.com>
> Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

Reviewed-by: Muchun Song <songmuchun@bytedance.com>