diff options
Diffstat (limited to 'bench/MHz.c')
| -rw-r--r-- | bench/MHz.c | 37 |
1 files changed, 14 insertions, 23 deletions
diff --git a/bench/MHz.c b/bench/MHz.c index 87315a9..187aa28 100644 --- a/bench/MHz.c +++ b/bench/MHz.c @@ -17,11 +17,14 @@ #include "../x86info.h" -static unsigned long long int rdtsc(void) +static inline unsigned long long int rdtsc(void) { - unsigned long long int x; - __asm__ volatile (".byte 0x0f, 0x31" : "=A" (x)); - return x; + unsigned int low, high; + unsigned long tsc; + + __asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high)); + tsc = ((unsigned long long) high << 32) | low; + return tsc; } static volatile int nosignal = 0; @@ -34,13 +37,9 @@ static void sighandler(int sig __attribute__((unused))) void estimate_MHz(struct cpudata *cpu) { cpu_set_t set; - struct timezone tz; - struct timeval tvstart, tvstop; unsigned long long int cycles[2]; /* gotta be 64 bit */ - unsigned long microseconds; /* total time taken */ unsigned int eax, ebx, ecx, edx; - unsigned long freq = 1; - unsigned long i; + unsigned long r; /* Make sure we have a TSC (and hence RDTSC) */ cpuid(cpu->number, 1, &eax, &ebx, &ecx, &edx); @@ -50,8 +49,6 @@ void estimate_MHz(struct cpudata *cpu) return; } - memset(&tz, 0, sizeof(tz)); - if (sched_getaffinity(getpid(), sizeof(set), &set) == 0) { CPU_ZERO(&set); CPU_SET(cpu->number, &set); @@ -64,25 +61,19 @@ void estimate_MHz(struct cpudata *cpu) } cycles[0] = rdtsc(); - gettimeofday(&tvstart, &tz); - alarm(3); - while (!nosignal) { - i = i * rand(); - } + alarm(1); + while (!nosignal) + r = r * rand(); - cycles[1] = rdtsc(); - gettimeofday(&tvstop, &tz); + nosignal = 0; - microseconds = ((tvstop.tv_sec-tvstart.tv_sec)*1000000) + - (tvstop.tv_usec-tvstart.tv_usec); + cycles[1] = rdtsc(); - cpu->MHz = (int) (cycles[1]-cycles[0]) / (microseconds/freq); + cpu->MHz = (cycles[1] - cycles[0]) / 1000000; if ((cpu->MHz % 50) > 15) cpu->MHz = ((cpu->MHz / 50) * 50) + 50; else cpu->MHz = ((cpu->MHz / 50) * 50); - - nosignal = 0; } |