Re: [RFC PATCH 03/24] mm/hugetlb: Introduce a new config HUGETLB_PAGE_FREE_VMEMMAP
From: Randy Dunlap <hidden>
Date: 2020-09-16 02:14:04
Also in:
linux-fsdevel, linux-mm, lkml
On 9/15/20 5:59 AM, Muchun Song wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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