Re: [PATCH RESEND v1 1/4] lib/vdso: Mark do_hres_timens() and do_coarse_timens() __always_inline()

Vincenzo Frascino
2021-04-12T12:55:06Z

On 3/31/21 5:48 PM, Christophe Leroy wrote:
> In the same spirit as commit c966533f8c6c ("lib/vdso: Mark do_hres()
> and do_coarse() as __always_inline"), mark do_hres_timens() and
> do_coarse_timens() __always_inline.
>
> The measurement below in on a non timens process, ie on the fastest path.
>
> On powerpc32, without the patch:
>
> clock-gettime-monotonic-raw: vdso: 1155 nsec/call
> clock-gettime-monotonic-coarse: vdso: 813 nsec/call
> clock-gettime-monotonic: vdso: 1076 nsec/call
>
> With the patch:
>
> clock-gettime-monotonic-raw: vdso: 1100 nsec/call
> clock-gettime-monotonic-coarse: vdso: 667 nsec/call
> clock-gettime-monotonic: vdso: 1025 nsec/call
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
> lib/vdso/gettimeofday.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
> index 2919f1698140..c6f6dee08746 100644
> --- a/lib/vdso/gettimeofday.c
> +++ b/lib/vdso/gettimeofday.c
> @@ -46,8 +46,8 @@ static inline bool vdso_cycles_ok(u64 cycles)
> #endif
>
> #ifdef CONFIG_TIME_NS
> -static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
> - struct __kernel_timespec *ts)
> +static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
> + struct __kernel_timespec *ts)
> {
> const struct vdso_data *vd = __arch_get_timens_vdso_data();
> const struct timens_offset *offs = &vdns->offset[clk];
> @@ -97,8 +97,8 @@ static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
> return NULL;
> }
>
> -static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
> - struct __kernel_timespec *ts)
> +static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
> + struct __kernel_timespec *ts)
> {
> return -EINVAL;
> }
> @@ -159,8 +159,8 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
> }
>
> #ifdef CONFIG_TIME_NS
> -static int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
> - struct __kernel_timespec *ts)
> +static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
> + struct __kernel_timespec *ts)
> {
> const struct vdso_data *vd = __arch_get_timens_vdso_data();
> const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
> @@ -188,8 +188,8 @@ static int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
> return 0;
> }
> #else
> -static int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
> - struct __kernel_timespec *ts)
> +static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
> + struct __kernel_timespec *ts)
> {
> return -1;
> }
>

--
Regards,
Vincenzo