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 mmap() 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 bgardon@google.com Cc: Ingo Molnar mingo@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Jiri Olsa jolsa@redhat.com Cc: Arnaldo Carvalho de Melo acme@redhat.com Cc: Arnd Bergmann arnd@arndb.de Cc: Michael Kerrisk mtk.manpages@gmail.com Cc: Thomas Gleixner tglx@linutronix.de Suggested-by: Ben Gardon bgardon@google.com Signed-off-by: Yanan Wang wangyanan55@huawei.com Reviewed-by: Ben Gardon bgardon@google.com --- 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 */