Re: [PATCH 01/19] vdso: Consolidate vdso_calc_delta()

[John Stultz]

On Fri, Mar 8, 2024 at 5:15 AM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>
> Consolidate vdso_calc_delta(), in preparation for further simplification.
>
> Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
>  arch/powerpc/include/asm/vdso/gettimeofday.h | 17 ++---------------
>  arch/s390/include/asm/vdso/gettimeofday.h    |  7 ++-----
>  lib/vdso/gettimeofday.c                      |  4 ++++
>  3 files changed, 8 insertions(+), 20 deletions(-)
>
> --- a/lib/vdso/gettimeofday.c
> +++ b/lib/vdso/gettimeofday.c
> @@ -13,7 +13,11 @@
>  static __always_inline
>  u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
>  {
> +#ifdef VDSO_DELTA_NOMASK
> +       return (cycles - last) * mult;
> +#else
>         return ((cycles - last) & mask) * mult;
> +#endif
>  }

Nit: Just for readability, usually we avoid #ifdefs inside of functions.

Instead maybe:
#ifdef VDSO_DELTA_NOMASK
static __always_inline
u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
 {
       return (cycles - last) * mult;
 }
#else
static __always_inline
u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
 {
      return ((cycles - last) & mask) * mult;
 }
#endif