From: Muchun Song Subject: mm: hugetlb_vmemmap: introduce ARCH_WANT_HUGETLB_PAGE_FREE_VMEMMAP 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. Link: https://lkml.kernel.org/r/20220331065640.5777-1-songmuchun@bytedance.com Signed-off-by: Muchun Song Suggested-by: Andrew Morton Reviewed-by: Barry Song Tested-by: Barry Song Reviewed-by: Anshuman Khandual Cc: Bodeddula Balasubramaniam Cc: Catalin Marinas Cc: David Hildenbrand Cc: David Rientjes Cc: Fam Zheng Cc: James Morse Cc: Mark Rutland Cc: Mike Kravetz Cc: Oscar Salvador Cc: Will Deacon Cc: Xiongchun Duan Signed-off-by: Andrew Morton --- arch/x86/Kconfig | 1 + fs/Kconfig | 10 +++++++++- 2 files changed, 10 insertions(+), 1 deletion(-) --- a/arch/x86/Kconfig~mm-hugetlb_vmemmap-introduce-arch_want_hugetlb_page_free_vmemmap +++ a/arch/x86/Kconfig @@ -121,6 +121,7 @@ config X86 select ARCH_WANTS_NO_INSTR select ARCH_WANT_GENERAL_HUGETLB 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 --- a/fs/Kconfig~mm-hugetlb_vmemmap-introduce-arch_want_hugetlb_page_free_vmemmap +++ a/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 _