On 31.03.22 10:48, Muchun Song wrote: > On Thu, Mar 31, 2022 at 4:42 PM David Hildenbrand <david@xxxxxxxxxx> wrote: >> >> On 31.03.22 08:56, Muchun Song wrote: >>> The feature of minimizing overhead of struct page associated with each >>> HugeTLB page is implemented on x86_64, however, the infrastructure of >>> this feature is already there, we could easily enable it for other >>> architectures. Introduce ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP for other >>> architectures to be easily enabled. Just select this config if they >>> want to enable this feature. >>> >>> Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >>> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> >>> --- >>> arch/x86/Kconfig | 1 + >>> fs/Kconfig | 10 +++++++++- >>> 2 files changed, 10 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >>> index 9f5bd41bf660..e69d42528542 100644 >>> --- a/arch/x86/Kconfig >>> +++ b/arch/x86/Kconfig >>> @@ -119,6 +119,7 @@ config X86 >>> select ARCH_WANTS_DYNAMIC_TASK_STRUCT >>> select ARCH_WANTS_NO_INSTR >>> select ARCH_WANT_HUGE_PMD_SHARE >>> + select ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP if X86_64 >>> select ARCH_WANT_LD_ORPHAN_WARN >>> select ARCH_WANTS_THP_SWAP if X86_64 >>> select ARCH_HAS_PARANOID_L1D_FLUSH >>> diff --git a/fs/Kconfig b/fs/Kconfig >>> index 6c7dc1387beb..f6db2af33738 100644 >>> --- a/fs/Kconfig >>> +++ b/fs/Kconfig >>> @@ -245,9 +245,17 @@ config HUGETLBFS >>> config HUGETLB_PAGE >>> def_bool HUGETLBFS >>> >>> +# >>> +# Select this config option from the architecture Kconfig, if it is preferred >>> +# to enable the feature of minimizing overhead of struct page associated with >>> +# each HugeTLB page. >>> +# >>> +config ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP >>> + bool >>> + >>> config HUGETLB_PAGE_FREE_VMEMMAP >>> def_bool HUGETLB_PAGE >>> - depends on X86_64 >>> + depends on ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP >>> depends on SPARSEMEM_VMEMMAP >>> >>> config HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON >> >> >> I think something like "HUGETLB_OPTIMIZE_VMEMMAP" might be more >> expressive, but that would imply renaming the existing config knob. >> > > How about doing a full code cleanup in a separate series in the future? > Yeah. -- Thanks, David / dhildenb
