The purpose of introducing HUGETLB_PAGE_FREE_VMEMMAP is to configure whether to enable the feature of freeing unused vmemmap associated with HugeTLB pages. Now only support x86.
Signed-off-by: Muchun Song <[email protected]> --- arch/x86/mm/init_64.c | 2 +- fs/Kconfig | 16 ++++++++++++++++ 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 0a45f062826e..0435bee2e172 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1225,7 +1225,7 @@ static struct kcore_list kcore_vsyscall; static void __init register_page_bootmem_info(void) { -#ifdef CONFIG_NUMA +#if defined(CONFIG_NUMA) || defined(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP) int i; for_each_online_node(i) diff --git a/fs/Kconfig b/fs/Kconfig index 976e8b9033c4..5a4265ff2a86 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -245,6 +245,22 @@ 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 X86 + depends on HUGETLB_PAGE + depends on SPARSEMEM_VMEMMAP + depends on HAVE_BOOTMEM_INFO_NODE + help + There are many struct page structures associated with each HugeTLB + page. But we only use a few struct page structures. In this case, + it wastes some memory. It is better to free the unused struct page + 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 -- 2.20.1
