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SubjectRe: [patch V2 01/17] x86/vdso: Mark the TSC clocksource path likely
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On 2/7/20 12:38 PM, Thomas Gleixner wrote:
> Jumping out of line for the TSC clcoksource read is creating awful
> code. TSC is likely to be the clocksource at least on bare metal and the PV
> interfaces are sufficiently more work that the jump over the TSC read is
> just in the noise.
>

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

> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
> arch/x86/include/asm/vdso/gettimeofday.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/arch/x86/include/asm/vdso/gettimeofday.h
> +++ b/arch/x86/include/asm/vdso/gettimeofday.h
> @@ -243,7 +243,7 @@ static u64 vread_hvclock(void)
>
> static inline u64 __arch_get_hw_counter(s32 clock_mode)
> {
> - if (clock_mode == VCLOCK_TSC)
> + if (likely(clock_mode == VCLOCK_TSC))
> return (u64)rdtsc_ordered();
> /*
> * For any memory-mapped vclock type, we need to make sure that gcc
>

--
Regards,
Vincenzo

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