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