This adds the Kconfig to enable or disable high-granularity mapping. Each architecture must explicitly opt-in to it (via ARCH_WANT_HUGETLB_HIGH_GRANULARITY_MAPPING), but when opted in, HGM will be enabled by default if HUGETLB_PAGE is enabled. Signed-off-by: James Houghton <jthoughton@xxxxxxxxxx> diff --git a/fs/Kconfig b/fs/Kconfig index 2685a4d0d353..a072bbe3439a 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -246,6 +246,18 @@ config HUGETLBFS config HUGETLB_PAGE def_bool HUGETLBFS +config ARCH_WANT_HUGETLB_HIGH_GRANULARITY_MAPPING + bool + +config HUGETLB_HIGH_GRANULARITY_MAPPING + bool "HugeTLB high-granularity mapping support" + default n + depends on ARCH_WANT_HUGETLB_HIGH_GRANULARITY_MAPPING + help + HugeTLB high-granularity mapping (HGM) allows userspace to issue + UFFDIO_CONTINUE on HugeTLB mappings in PAGE_SIZE chunks. + HGM is incompatible with the HugeTLB Vmemmap Optimization (HVO). + # # Select this config option from the architecture Kconfig, if it is preferred # to enable the feature of HugeTLB Vmemmap Optimization (HVO). @@ -257,6 +269,7 @@ config HUGETLB_PAGE_OPTIMIZE_VMEMMAP def_bool HUGETLB_PAGE depends on ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP depends on SPARSEMEM_VMEMMAP + depends on !HUGETLB_HIGH_GRANULARITY_MAPPING config HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON bool "HugeTLB Vmemmap Optimization (HVO) defaults to on" -- 2.39.2.637.g21b0678d19-goog
