We know that if a system supports multiple hugetlb page sizes, the desired hugetlb page size can be specified in bits [26:31] of the flag arguments. The value in these 6 bits will be the shift of each hugetlb page size.
So add a macro to get the page size shift and then calculate the corresponding hugetlb page size, using flag x. Cc: Ben Gardon <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Michael Kerrisk <[email protected]> Cc: Thomas Gleixner <[email protected]> Suggested-by: Ben Gardon <[email protected]> Signed-off-by: Yanan Wang <[email protected]> Reviewed-by: Ben Gardon <[email protected]> --- include/uapi/linux/mman.h | 2 ++ tools/include/uapi/linux/mman.h | 2 ++ 2 files changed, 4 insertions(+) diff --git a/include/uapi/linux/mman.h b/include/uapi/linux/mman.h index f55bc680b5b0..d72df73b182d 100644 --- a/include/uapi/linux/mman.h +++ b/include/uapi/linux/mman.h @@ -41,4 +41,6 @@ #define MAP_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB #define MAP_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB +#define MAP_HUGE_PAGE_SIZE(x) (1ULL << ((x >> MAP_HUGE_SHIFT) & MAP_HUGE_MASK)) + #endif /* _UAPI_LINUX_MMAN_H */ diff --git a/tools/include/uapi/linux/mman.h b/tools/include/uapi/linux/mman.h index f55bc680b5b0..d72df73b182d 100644 --- a/tools/include/uapi/linux/mman.h +++ b/tools/include/uapi/linux/mman.h @@ -41,4 +41,6 @@ #define MAP_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB #define MAP_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB +#define MAP_HUGE_PAGE_SIZE(x) (1ULL << ((x >> MAP_HUGE_SHIFT) & MAP_HUGE_MASK)) + #endif /* _UAPI_LINUX_MMAN_H */ -- 2.19.1
