From cd9ddaaf321b2d6dcaf1f19df332952540cacb6d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 7 Feb 2020 13:38:48 +0100 Subject: [PATCH] x86/vdso: Mark the TSC clocksource path likely 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. Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino Link: https://lkml.kernel.org/r/20200207124402.328922847@linutronix.de --- arch/x86/include/asm/vdso/gettimeofday.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h index 6ee1f7dba34bf..264d4fd3ff2c5 100644 --- 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 -- 2.39.5