Add MapFlags::map_hugetlb_with_size_log2

src/sys/mman.rs

@@ -190,6 +190,31 @@ libc_bitflags! {
  }
 }
 
+impl MapFlags {
+ /// Create `MAP_HUGETLB` with provided size of huge page.
+ ///
+ /// Under the hood it computes `MAP_HUGETLB | (huge_page_size_log2 << libc::MAP_HUGE_SHIFT`).
+ /// `huge_page_size_log2` denotes logarithm of huge page size to use and should be
+ /// between 16 and 63 (inclusively).
+ ///
+ /// ```
+ /// # use nix::sys::mman::MapFlags;
+ /// let f = MapFlags::map_hugetlb_with_size_log2(30).unwrap();
+ /// assert_eq!(f, MapFlags::MAP_HUGETLB | MapFlags::MAP_HUGE_1GB);
+ /// ```
+ #[cfg(target_os = "linux")]
+ #[cfg_attr(docsrs, doc(cfg(all())))]
+ pub fn map_hugetlb_with_size_log2(huge_page_size_log2: u32) -> Option<Self> {
+ if (16..=63).contains(&huge_page_size_log2) {
+ let flag = libc::MAP_HUGETLB
+ | (huge_page_size_log2 << libc::MAP_HUGE_SHIFT) as i32;
+ Some(Self(flag.into()))
+ } else {
+ None
+ }
+ }
+}
+
 #[cfg(any(target_os = "linux", target_os = "netbsd"))]
 libc_bitflags! {
  /// Options for [`mremap`].