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    SubjectRE: [PATCH v3 1/2] mm: migration: fix the FOLL_GET failure on following huge page
    Date
    > -----Original Message-----
    > From: Huang, Ying <ying.huang@intel.com>
    > Sent: Monday, August 15, 2022 09:59
    > To: Wang, Haiyue <haiyue.wang@intel.com>
    > Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; akpm@linux-foundation.org; david@redhat.com;
    > linmiaohe@huawei.com; songmuchun@bytedance.com; naoya.horiguchi@linux.dev; alex.sierra@amd.com
    > Subject: Re: [PATCH v3 1/2] mm: migration: fix the FOLL_GET failure on following huge page
    >
    > Haiyue Wang <haiyue.wang@intel.com> writes:
    >
    > > Not all huge page APIs support FOLL_GET option, so the __NR_move_pages
    >
    > move_pages() is a syscall, so you can just call it move_pages(), or
    > move_pages() syscall.

    The application meets the issue, use the bellow function:
    syscall (__NR_move_pages, 0, n_pages, ptr, 0, status, 0)

    So I used it directly in the commit. "move_pages() syscall" is better.
    Will update latter.

    >
    > > will fail to get the page node information for huge page.
    > ~~~~~~~~~
    > some huge pages?

    OK.

    >
    > > This is an temporary solution to mitigate the racing fix.
    >
    > Why is it "racing fix"? This isn't a race condition fix.

    The 'Fixes' commit is about race condition fix.

    How about " his is an temporary solution to mitigate the side effect
    Of the race condition fix"

    >
    > Best Regards,
    > Huang, Ying
    >
    > > After supporting follow huge page by FOLL_GET is done, this fix can be
    > > reverted safely.
    > >
    > > Fixes: 4cd614841c06 ("mm: migration: fix possible do_pages_stat_array racing with memory offline")
    > > Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
    >
    > [snip]

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