Re: [PATCH v20 7/9] mm: hugetlb: add a kernel parameter hugetlb_free_vmemmap

[Mike Kravetz]

On 4/15/21 1:40 AM, Muchun Song wrote:
> Add a kernel parameter hugetlb_free_vmemmap to enable the feature of
> freeing unused vmemmap pages associated with each hugetlb page on boot.
> 
> We disables PMD mapping of vmemmap pages for x86-64 arch when this
> feature is enabled. Because vmemmap_remap_free() depends on vmemmap
> being base page mapped.
> 
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
> Reviewed-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
> Reviewed-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> Tested-by: Chen Huang <chenhuang5@xxxxxxxxxx>
> Tested-by: Bodeddula Balasubramaniam <bodeddub@xxxxxxxxxx>
> ---
>  Documentation/admin-guide/kernel-parameters.txt | 17 +++++++++++++++++
>  Documentation/admin-guide/mm/hugetlbpage.rst    |  3 +++
>  arch/x86/mm/init_64.c                           |  8 ++++++--
>  include/linux/hugetlb.h                         | 19 +++++++++++++++++++
>  mm/hugetlb_vmemmap.c                            | 24 ++++++++++++++++++++++++
>  5 files changed, 69 insertions(+), 2 deletions(-)

Thanks,

Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
-- 
Mike Kravetz