boinc/client/stream.cpp

332 lines
10 KiB
C++

// This file is part of BOINC.
// http://boinc.berkeley.edu
// Copyright (C) 2008 University of California
//
// BOINC is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License
// as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// BOINC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with BOINC. If not, see <http://www.gnu.org/licenses/>.
// Memory bandwidth benchmark derived from STREAM. Original copyright
// notice follows. Notice that we cannot call our results "STREAM
// benchmark results"
// Original Copyright Notice:
/*-----------------------------------------------------------------------*/
/* Program: Stream */
/* Revision: Id: stream.c,v 5.6 2005/10/04 00:19:59 mccalpin */
/* Original code developed by John D. McCalpin */
/* Programmers: John D. McCalpin */
/* Joe R. Zagar */
/* */
/* This program measures memory transfer rates in MB/s for simple */
/* computational kernels coded in C. */
/*-----------------------------------------------------------------------*/
/* Copyright 1991-2005: John D. McCalpin */
/*-----------------------------------------------------------------------*/
/* License: */
/* 1. You are free to use this program and/or to redistribute */
/* this program. */
/* 2. You are free to modify this program for your own use, */
/* including commercial use, subject to the publication */
/* restrictions in item 3. */
/* 3. You are free to publish results obtained from running this */
/* program, or from works that you derive from this program, */
/* with the following limitations: */
/* 3a. In order to be referred to as "STREAM benchmark results", */
/* published results must be in conformance to the STREAM */
/* Run Rules, (briefly reviewed below) published at */
/* http://www.cs.virginia.edu/stream/ref.html */
/* and incorporated herein by reference. */
/* As the copyright holder, John McCalpin retains the */
/* right to determine conformity with the Run Rules. */
/* 3b. Results based on modified source code or on runs not in */
/* accordance with the STREAM Run Rules must be clearly */
/* labelled whenever they are published. Examples of */
/* proper labelling include: */
/* "tuned STREAM benchmark results" */
/* "based on a variant of the STREAM benchmark code" */
/* Other comparable, clear and reasonable labelling is */
/* acceptable. */
/* 3c. Submission of results to the STREAM benchmark web site */
/* is encouraged, but not required. */
/* 4. Use of this program or creation of derived works based on this */
/* program constitutes acceptance of these licensing restrictions. */
/* 5. Absolutely no warranty is expressed or implied. */
/*-----------------------------------------------------------------------*/
# include <cstdio>
# include <cmath>
# include <float.h>
# include <climits>
# include <sys/time.h>
# include <cstdlib>
# include <algorithm>
static int N=64;
static const int NTIMES(10);
static const int OFFSET(0);
static double avgtime[4] = {0}, maxtime[4] = {0},
mintime[4] = {FLT_MAX,FLT_MAX,FLT_MAX,FLT_MAX};
static char *label[4] = {"Copy: ", "Scale: ",
"Add: ", "Triad: "};
static double bytes[4] = {
2 * sizeof(double) * N,
2 * sizeof(double) * N,
3 * sizeof(double) * N,
3 * sizeof(double) * N
};
extern double mysecond();
extern double checktick();
extern void checkSTREAMresults(double *a,double *b, double *c);
void mem_bw(double &avg_bw, double &cache_size) {
avg_bw=0;
double *a=(double *)malloc((N+OFFSET)*sizeof(double));
double *b=(double *)malloc((N+OFFSET)*sizeof(double));
double *c=(double *)malloc((N+OFFSET)*sizeof(double));
double quantum=checktick();
int BytesPerWord;
register int j, k;
double scalar, t, times[4][NTIMES];
double rv=0;
double tt[30],t_max;
int cache_ratio=1,cache_level=1;
int i=0;
int check_cache=(cache_size==0);
do {
N*=2;
a=(double *)realloc(a,(N+OFFSET)*sizeof(double));
b=(double *)realloc(b,(N+OFFSET)*sizeof(double));
c=(double *)realloc(c,(N+OFFSET)*sizeof(double));
if ( !a || !b || !c ) return;
for (j=0; j<N; j++) {
a[j] = 1.0;
b[j] = 2.0;
c[j] = 0.0;
}
long transfer=0;
// get as close to a clock boundary as possible
t = mysecond();
while ((t-mysecond())==0); // do nothing
double t0 = mysecond();
do {
for (j = 0; j < N; j++)
a[j] = 2.0E0 * a[j];
t = 1.0E6 * (mysecond() - t0);
transfer++;
} while (t < 10*quantum); // run at least a 10 ticks.
t/=transfer; // change to "per run" time
tt[i++]=t;
t_max=std::max(N/t,t_max);
if (check_cache) {
if ((cache_ratio*N)<(t*t_max)) {
cache_size=N/2*sizeof(double);
cache_ratio*=2;
// printf("Level %d Cache Size = %f bytes\n",cache_level++,*cache_size);
}
}
} while (t<1e5);
bytes[0]=bytes[1]=2 * sizeof(double) * N;
bytes[2]=bytes[3]=3 * sizeof(double) * N;
/* --- MAIN LOOP --- repeat test cases NTIMES times --- */
scalar = 3.0;
for (k=0; k<NTIMES; k++) {
times[0][k] = mysecond();
for (j=0; j<N; j++)
c[j] = a[j];
times[0][k] = mysecond() - times[0][k];
times[1][k] = mysecond();
for (j=0; j<N; j++)
b[j] = scalar*c[j];
times[1][k] = mysecond() - times[1][k];
times[2][k] = mysecond();
for (j=0; j<N; j++)
c[j] = a[j]+b[j];
times[2][k] = mysecond() - times[2][k];
times[3][k] = mysecond();
for (j=0; j<N; j++)
a[j] = b[j]+scalar*c[j];
times[3][k] = mysecond() - times[3][k];
}
/* --- SUMMARY --- */
for (k=1; k<NTIMES; k++) /* note -- skip first iteration */
{
for (j=0; j<4; j++) {
avgtime[j] = avgtime[j] + times[j][k];
mintime[j] = std::min(mintime[j], times[j][k]);
maxtime[j] = std::max(maxtime[j], times[j][k]);
}
}
printf("Function Rate (MB/s) Avg time Min time Max time\n");
for (j=0; j<4; j++) {
avgtime[j] = avgtime[j]/(double)(NTIMES-1);
printf("%s%11.4f %11.4f %11.4f %11.4f\n", label[j],
1.0E-06 * bytes[j]/mintime[j],
avgtime[j],
mintime[j],
maxtime[j]);
avg_bw+=(double)bytes[j]/mintime[j];
}
avg_bw/=4;
/* --- Check Results --- */
checkSTREAMresults(a,b,c);
}
# define M 20
double checktick() {
int i;
double minDelta, Delta;
double t1, t2, timesfound[M];
/* Collect a sequence of M unique time values from the system. */
for (i = 0; i < M; i++) {
t1 = mysecond();
while( ((t2=mysecond()) - t1) < 1.0E-6 )
;
timesfound[i] = t1 = t2;
}
/*
* Determine the minimum difference between these M values.
* This result will be our estimate (in microseconds) for the
* clock granularity.
*/
minDelta = 1000000;
for (i = 1; i < M; i++) {
Delta = ( 1.0E6 * (timesfound[i]-timesfound[i-1]));
minDelta = std::min(minDelta, std::max(Delta,0.0));
}
return(minDelta);
}
/* A gettimeofday routine to give access to the wall
clock timer on most UNIX-like systems. */
#include <sys/time.h>
double mysecond() {
struct timeval tp;
struct timezone tzp;
int i;
i = gettimeofday(&tp,&tzp);
return ( (double) tp.tv_sec + (double) tp.tv_usec * 1.e-6 );
}
void checkSTREAMresults (double *a, double *b, double *c) {
double aj,bj,cj,scalar;
double asum,bsum,csum;
double epsilon;
int j,k;
/* reproduce initialization */
aj = 1.0;
bj = 2.0;
cj = 0.0;
/* a[] is modified during timing check */
aj = 2.0E0 * aj;
/* now execute timing loop */
scalar = 3.0;
for (k=0; k<NTIMES; k++) {
cj = aj;
bj = scalar*cj;
cj = aj+bj;
aj = bj+scalar*cj;
}
aj = aj * (double) (N);
bj = bj * (double) (N);
cj = cj * (double) (N);
asum = 0.0;
bsum = 0.0;
csum = 0.0;
for (j=0; j<N; j++) {
asum += a[j];
bsum += b[j];
csum += c[j];
}
#ifdef VERBOSE
printf ("Results Comparison: \n");
printf (" Expected : %f %f %f \n",aj,bj,cj);
printf (" Observed : %f %f %f \n",asum,bsum,csum);
#endif
#ifndef abs
#define abs(a) ((a) >= 0 ? (a) : -(a))
#endif
epsilon = 1.e-8;
if (abs(aj-asum)/asum > epsilon) {
printf ("Failed Validation on array a[]\n");
printf (" Expected : %f \n",aj);
printf (" Observed : %f \n",asum);
} else if (abs(bj-bsum)/bsum > epsilon) {
printf ("Failed Validation on array b[]\n");
printf (" Expected : %f \n",bj);
printf (" Observed : %f \n",bsum);
} else if (abs(cj-csum)/csum > epsilon) {
printf ("Failed Validation on array c[]\n");
printf (" Expected : %f \n",cj);
printf (" Observed : %f \n",csum);
} else {
printf ("Solution Validates\n");
}
}
#ifdef STREAM_TEST
int main() {
double cache_size=0;
double avg_bw=0;
mem_bw(avg_bw,cache_size);
printf("Average bandwidth=%f MB/s\n",avg_bw/1024/1024);
printf("Cache Size=%f kB\n",cache_size/1024);
}
#endif