Hi Here is my way of measuring the total power consumption on Xeon Phi. But the performance result seems not to be so reasonable. I use "Total power, win 0 uW" as the parameter for measurements. The code use one pthread to read the power in uW every 50 milliseconds since /sys/class/micras/power updated in around 50 milliseconds. Each time power watt updated, I update the energy with adding 50*power. Anything wrong with this measurement in measuring the total power consumption?
The thing is that for dgemm call in MKL I measure the dense matrix with 5000*2500 matrix times 2500*5000 matrix. The result I have comparing with CPU energy consumption is not that make sense to me.
Intel MIC 5110P : 59.00 Joules in 459.843 milliseconds with 156.57 GFLOPS. So the GFLOPS/Watt=156.57/(59.00/(459.843/1000))=1.2202GFLOPS/Watt
Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz: 60.89 Joules in 798.345 milliseconds with 271.831 GFLOPS. So the GFLOPS/Watt = 271.831/(60.89/(798.345/1000))=3.564 GFLOPS/Watt. Intel(R) Xeon(R) CPU power is measured by PAPI RAPL PACKAGE_ENERGY:PACKAGE0 event.
http://www.intel.com/content/dam/www/public/us/en/documents/performance-briefs/xeon-phi-product-family-performance-brief.pdf The performance per watt reported on above document on DGEMM call is for MIC is above 4 while for CPU is less than 1.5 GFLOPS/Watt.
micpowerSample.cc
// -sh-4.2$ cat /sys/class/micras/power
// 104000000 //Total power, win 0 uW
// 104000000 //Total power, win 1 uW
// 106000000 //PCI-E connector power
// 217000000 //Instantaneous power uW
// 32000000 //Max Instantaneous power
// 26000000 //2x3 connector power
// 48000000 //2x4 connector power
// 1) Core rail; Power reading(uW)
// 2) Core rail; Current(uA)
// 3) Core rail; Voltage(uV)
// 24000000 0 995000
// 33000000 0 1000000 //Uncore rail; Power reading, Current, Voltage
// 32000000 0 1501000 //Memory subsystem rail; Power reading, Current, Voltage
#define MICPOWER_MAX_COUNTERS 16
typedef struct MICPOWER_control_state {
long long counts[MICPOWER_MAX_COUNTERS]; // used for caching
long long lastupdate;
} MICPOWER_control_state_t;
static int read_sysfs_file(long long* counts) {
FILE* fp = NULL;
int i;
int retval = 1;
fp = fopen("/sys/class/micras/power", "r");
if (!fp)
return 0;
for (i=0; i < MICPOWER_MAX_COUNTERS-9; i++) {
retval &= fscanf(fp, "%lld", &counts);
}
for (i = MICPOWER_MAX_COUNTERS - 9; i < MICPOWER_MAX_COUNTERS; i += 3) {
retval &= fscanf(fp, "%lld %lld %lld", &counts, &counts[i+1], &counts[i+2]);
}
fclose(fp);
return retval;
}
volatile bool keepAlive = true;
double passEnergy = 0.0;
void* recordEnergy(void *arg) {
int retval = 0;
long long counts[MICPOWER_MAX_COUNTERS]; // used for caching
struct timespec ts;
ts.tv_sec = 0;
ts.tv_nsec = 50000000L; // 50 milliseconds
double energy = 0.0;
while (keepAlive) {
retval = read_sysfs_file(counts);
energy += counts[0];
nanosleep(&ts, NULL);
}
keepAlive = true;
passEnergy = energy;
printf("Energy used in %lf\n", energy * 50.0 / 1000 / 1000 / 1000);
energy = 0.0;
}
pthread_t micPthread;
void micpower_start() {
int iret1 = pthread_create(&micPthread, NULL, recordEnergy, (void*)NULL);
}
double micpower_finalize() {
keepAlive = false;
pthread_join(micPthread, NULL);
return passEnergy * 50.0 / 1000 / 1000 / 1000;
}
// int main() {
// micpower_start();
// long long sum = 0;
// double la = 9.0;
// for (int j = 0; j < 500; ++j) {
// for (int i = 0; i < 100000; ++i) {
// sum += i;
// la = la * i / 60.0;
// }
// }
// double energy = micpower_finalize();
// return 0;
// }
//
