On Tue, Mar 02, 2021 at 08:57:44PM +0800, Yanan Wang wrote: > 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 <bgardon@xxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx> > Cc: Jiri Olsa <jolsa@xxxxxxxxxx> > Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> > Cc: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Suggested-by: Ben Gardon <bgardon@xxxxxxxxxx> > Signed-off-by: Yanan Wang <wangyanan55@xxxxxxxxxx> > Reviewed-by: Ben Gardon <bgardon@xxxxxxxxxx> > --- > 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..8bd41128a0ee 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) (1 << ((x >> MAP_HUGE_SHIFT) & MAP_HUGE_MASK)) Needs to be '1ULL' to avoid shift overflow when given MAP_HUGE_16GB. Thanks, drew > + > #endif /* _UAPI_LINUX_MMAN_H */ > diff --git a/tools/include/uapi/linux/mman.h b/tools/include/uapi/linux/mman.h > index f55bc680b5b0..8bd41128a0ee 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) (1 << ((x >> MAP_HUGE_SHIFT) & MAP_HUGE_MASK)) > + > #endif /* _UAPI_LINUX_MMAN_H */ > -- > 2.23.0 >
