On 9/15/20 5:59 AM, Muchun Song wrote:
> The purpose of introducing HUGETLB_PAGE_FREE_VMEMMAP is to configure
> whether to enable the feature of freeing unused vmemmap associated
> with HugeTLB pages.
>
> Signed-off-by: Muchun Song <[email protected]>
> ---
> fs/Kconfig | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/fs/Kconfig b/fs/Kconfig
> index 976e8b9033c4..61e9c08096ca 100644
> --- a/fs/Kconfig
> +++ b/fs/Kconfig
> @@ -245,6 +245,21 @@ config HUGETLBFS
> config HUGETLB_PAGE
> def_bool HUGETLBFS
>
> +config HUGETLB_PAGE_FREE_VMEMMAP
> + bool "Free unused vmemmap associated with HugeTLB pages"
> + default n
> + depends on HUGETLB_PAGE
> + depends on SPARSEMEM_VMEMMAP
> + depends on HAVE_BOOTMEM_INFO_NODE
> + help
> + There are many struct page structure associated with each HugeTLB
structures
> + page. But we only use a few struct page structure. In this case,
structures.
> + it waste some memory. It is better to free the unused struct page
it wastes
> + structures to buddy system which can save some memory. For
> + architectures that support it, say Y here.
> +
> + If unsure, say N.
> +
> config MEMFD_CREATE
> def_bool TMPFS || HUGETLBFS
>
>
--
~Randy
