Messages in this thread | | | Subject | Re: [RFC PATCH v4 2/9] tools headers: Add a macro to get HUGETLB page sizes for mmap | From | "wangyanan (Y)" <> | Date | Mon, 15 Mar 2021 10:06:33 +0800 |
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On 2021/3/12 19:14, Andrew Jones wrote: > 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@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..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. Will fix it. > 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 >> > .
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