1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <float.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/resource.h>
/****************************************************
* Random generate a random int between _Min and _Max
*/
int Random(int _iMin,int _iMax)
{
return (_iMin + (rand()%(_iMax-_iMin+1)));
}
/****************************************************
* Return the struct of getrusage.
*/
struct rusage give_ru()
{
struct rusage ru;
getrusage(RUSAGE_SELF, &ru);
//getrusage(RUSAGE_CHILDREN, &ru);
return ru;
}
/****************************************************
* Do a matrix multiplication a*b=c
* This program isn't optimized.
*/
int main()
{
/*
* Initialize variables and array sizes.
*/
int **a,**b,**c;
printf("\nenter Taille de la matrice : 2500");
int a_r=2500,a_c=2500,b_r=2500,b_c=2500;
clock_t start,end;
struct rusage start1,end1;
/* variables to store time difference between
start of matrix multiplication and end of multiplication. */
double dif; /*variable to calculate the time difference between the parallelization */
int i,j,k;
again:
printf("\nenter rows and columns for matrix one:");
//scanf("%d%d",&a_r,&a_c);
printf("\nenter rows and columns for matrix two:");
//scanf("%d%d",&b_r,&b_c);
if(a_c!=b_r )
{
printf("\ncan not multiply");
goto again;
}
/*
* Memory allocation.
*/
start =clock();
/* allocate memory for matrix one */
a=(int **) malloc(10*a_r);
for( i=0;i<a_c; i++)
{
a[i]=(int *) malloc(10*a_c);
}
/* allocate memory for matrix two */
b=(int **) malloc(10*b_r);
for( i=0;i<b_c; i++)
{
b[i]=(int *) malloc(10*b_c);
}
/* allocate memory for sum matrix */
c=(int **) malloc(10*a_r);
for( i=0;i< b_c; i++)
{
c[i]=(int *) malloc(10*b_c);
}
/* Memory is lock*/
printf("Starting mlockall.\n");
if(mlockall(MCL_CURRENT | MCL_FUTURE)<0) {
perror("mlockall");
return 1;
}
/*
* Matrix initialization (with random integer).
*/
printf("Initializing matrices...\n");
//initializing first matrix
for(i=0;i<a_r; i++)
{
for(j=0;j<a_c; j++)
{
a[i][j] = Random(0,100);//i+j;
}
}
// initializing second matrix
for(i=0;i<b_r; i++)
{
for(j=0;j<b_c; j++)
{
b[i][j] = Random(0,100);//i*j;
}
}
/*initialize product matrix */
for(i=0;i<a_r; i++)
{
for(j=0;j< b_c; j++)
{
c[i][j]=Random(0,100);//0;
}
}
end= clock(); //end the timer
dif = ((double) (end - start)) / CLOCKS_PER_SEC; //store the difference
printf("Malloc and initialization took %f sec. time.\n", dif);
/*
* Matrix Multiplication.
*/
start =clock(); //start the timer
start1 = give_ru(); //start the timer
/* multiply matrix one and matrix two */
for(i=0;i<a_r; i++)
for(j=0;j<a_c; j++)
for(k=0;k<b_c; k++)
c[i][j]=c[i][j]+a[i][k]*b[k][j];
end1 = give_ru(); //end the timer
end = clock(); //end the timer
dif = ((double) (end - start)) / CLOCKS_PER_SEC; //store the difference
struct timeval timeUserStart = start1.ru_utime;
double utimeStart = (double)timeUserStart.tv_sec + (double)timeUserStart.tv_usec / 1000000.0;
struct timeval timeSystemStart = start1.ru_stime;
double stimeStart = (double)timeSystemStart.tv_sec + (double)timeSystemStart.tv_usec / 1000000.0;
struct timeval timeUserEnd = end1.ru_utime;
double utimeEnd = (double)timeUserEnd.tv_sec + (double)timeUserEnd.tv_usec / 1000000.0;
struct timeval timeSystemEnd = end1.ru_stime;
double stimeEnd = (double)timeSystemEnd.tv_sec + (double)timeSystemEnd.tv_usec / 1000000.0;
double difuTime = utimeEnd - utimeStart;
double difsTime = stimeEnd - stimeStart;
long pageReclaims = end1.ru_minflt;//start1.ru_minflt-
long pageFaults = end1.ru_majflt;//start1.ru_majflt-
printf("Parallelization took %f sec. time.\n", dif);
printf("Time User : %f .\n", difuTime );
printf("Time System : %f .\n", difsTime );
printf("Page reclaims : %ld .\n", end1.ru_minflt);
printf("Page faults : %ld .\n", end1.ru_majflt);
/*
* free memory.
*/
printf("Finished, cleaning up \n");
munlockall();
/*free memory*/
for(i=0;i<a_r; i++)
{
free(a[i]);
}
free(a);
for(i=0;i<a_c; i++)
{
free(b[i]);
}
free(b);
for(i=0;i<b_c; i++)
{
free(c[i]);
}
free(c);
return 0;
} |
Pourquoi le temps d'exécution d'une multiplication matricielle varie-t-il ?
Répondre avec citation
Envoyé par Obsidian
Mon programme n'est pas du tout optimisé, c'est un choix volontaire comme je m'intéresse à pourquoi le temps d'exécution varie dans différent cas (comme je l'expliquais au début du message).
Partager