c818a18146
RDTSC serialization using cpuid is not needed for Intel platforms. This increases gettimeofday performance. Cc: vojtech@suse.cz Cc: rohit.seth@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
/*
|
|
* linux/include/asm-x86_64/timex.h
|
|
*
|
|
* x86-64 architecture timex specifications
|
|
*/
|
|
#ifndef _ASMx8664_TIMEX_H
|
|
#define _ASMx8664_TIMEX_H
|
|
|
|
#include <asm/8253pit.h>
|
|
#include <asm/msr.h>
|
|
#include <asm/vsyscall.h>
|
|
#include <asm/hpet.h>
|
|
#include <asm/system.h>
|
|
#include <asm/processor.h>
|
|
#include <linux/compiler.h>
|
|
|
|
#define CLOCK_TICK_RATE PIT_TICK_RATE /* Underlying HZ */
|
|
|
|
typedef unsigned long long cycles_t;
|
|
|
|
static inline cycles_t get_cycles (void)
|
|
{
|
|
unsigned long long ret;
|
|
|
|
rdtscll(ret);
|
|
return ret;
|
|
}
|
|
|
|
/* Like get_cycles, but make sure the CPU is synchronized. */
|
|
static __always_inline cycles_t get_cycles_sync(void)
|
|
{
|
|
unsigned long long ret;
|
|
unsigned eax;
|
|
/* Don't do an additional sync on CPUs where we know
|
|
RDTSC is already synchronous. */
|
|
alternative_io(ASM_NOP2, "cpuid", X86_FEATURE_SYNC_RDTSC,
|
|
"=a" (eax), "0" (1) : "ebx","ecx","edx","memory");
|
|
rdtscll(ret);
|
|
return ret;
|
|
}
|
|
|
|
extern unsigned int cpu_khz;
|
|
|
|
extern int read_current_timer(unsigned long *timer_value);
|
|
#define ARCH_HAS_READ_CURRENT_TIMER 1
|
|
|
|
extern struct vxtime_data vxtime;
|
|
|
|
#endif
|