On Fri, 2017-05-26 at 12:09 +0200, Mariusz Skamra wrote:
> This simplifies ktime_compare, ktime_after and ktime_before to be defines.
> ktime_compare verified on x86_64 machine, gives a code 4 asm instruction
> less compared to the previous solution. Time measured is up to 2 times less.
> Signed-off-by: Mariusz Skamra <[email protected]>
> Acked-by: Kuppuswamy Sathyanarayanan <[email protected]>
> ---
> include/linux/ktime.h | 19 +++----------------
> 1 file changed, 3 insertions(+), 16 deletions(-)
>
> diff --git a/include/linux/ktime.h b/include/linux/ktime.h
> index 0c8bd45..3f3dfcd 100644
> --- a/include/linux/ktime.h
> +++ b/include/linux/ktime.h
> @@ -106,14 +106,7 @@ static inline ktime_t timeval_to_ktime(struct timeval tv)
> * cmp1 == cmp2: return 0
> * cmp1 > cmp2: return >0
> */
> -static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
> -{
> - if (cmp1 < cmp2)
> - return -1;
> - if (cmp1 > cmp2)
> - return 1;
> - return 0;
> -}
> +#define ktime_compare(cmp1, cmp2) ktime_sub(cmp1, cmp2)
Why not just change ktime_compare to
static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
{
return ktime_sub(cmp1, cmp2);
}
>
> /**
> * ktime_after - Compare if a ktime_t value is bigger than another one.
> @@ -122,10 +115,7 @@ static inline int ktime_compare(const ktime_t cmp1,
> const ktime_t cmp2)
> *
> * Return: true if cmp1 happened after cmp2.
> */
> -static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2)
> -{
> - return ktime_compare(cmp1, cmp2) > 0;
> -}
> +#define ktime_after(cmp1, cmp2) (ktime_compare(cmp1, cmp2) > 0)
The ktime_after and ktime_before changes shouldn't
matter in generated objects.
I suggest these conversions from static inline to
#define are not changes for the better.
> /**
> * ktime_before - Compare if a ktime_t value is smaller than another one.
> @@ -134,10 +124,7 @@ static inline bool ktime_after(const ktime_t cmp1, const
> ktime_t cmp2)
> *
> * Return: true if cmp1 happened before cmp2.
> */
> -static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
> -{
> - return ktime_compare(cmp1, cmp2) < 0;
> -}
> +#define ktime_before(cmp1, cmp2) (ktime_compare(cmp1, cmp2) < 0)
>
> #if BITS_PER_LONG < 64
> extern s64 __ktime_divns(const ktime_t kt, s64 div);
