Commit b20e8571eeebb9546bf966a988355f09ee715b20
1 parent
88a6d902f9
Exists in
master
imemory access time
Showing 2 changed files with 14 additions and 10 deletions Side-by-side Diff
memory/memory_access_time.c
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b20e857
| ... | ... | @@ -8,38 +8,42 @@ |
| 8 | 8 | #define STRIDE_SIZE 16 |
| 9 | 9 | #define CPU_FREQ 900 |
| 10 | 10 | |
| 11 | -unsigned access_time_1(int size, int stride_size){ | |
| 11 | +unsigned long long access_time_1(int size, int stride_size){ | |
| 12 | 12 | struct timeval start, end; |
| 13 | 13 | struct timezone tz; |
| 14 | - unsigned time1, time2; | |
| 14 | + unsigned long long time1, time2; | |
| 15 | 15 | int j; |
| 16 | 16 | int *array = (int *)malloc(size); |
| 17 | 17 | int len = (size)/sizeof(int); |
| 18 | 18 | unsigned int i; |
| 19 | + for(i=0; i < MAX_ARRAY_SIZE; i++) { | |
| 20 | + array[( i * stride_size) % len] = array[( i * stride_size) % len]+i; | |
| 21 | + } | |
| 19 | 22 | |
| 20 | - //gettimeofday(&start, &tz); | |
| 21 | - asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (time1)); | |
| 23 | + gettimeofday(&start, NULL); | |
| 24 | + //asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (time1)); | |
| 22 | 25 | for(i=0; i < MAX_ARRAY_SIZE; i++) { |
| 23 | 26 | j = array[( i * stride_size) % len]; |
| 24 | - j++; | |
| 25 | 27 | } |
| 26 | - //gettimeofday(&end, &tz); | |
| 27 | - asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (time2)); | |
| 28 | + gettimeofday(&end, NULL); | |
| 29 | + //asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r" (time2)); | |
| 28 | 30 | |
| 29 | 31 | free(array); |
| 30 | - return time2-time1; | |
| 32 | + //return time2-time1; | |
| 33 | + return (-start.tv_sec*1e6-start.tv_usec+end.tv_sec*1e6+end.tv_usec); | |
| 31 | 34 | } |
| 32 | 35 | |
| 33 | 36 | int main() |
| 34 | 37 | { |
| 35 | 38 | int i, j; |
| 36 | 39 | |
| 37 | - for (j = 4; j <= 1024; j*=2) { | |
| 40 | + for (j = 128; j <= 1024; j*=2) { | |
| 38 | 41 | printf("Stride size: %u\n", j); |
| 39 | 42 | for (i = 1024; i <= 32 * MB; i*=2) { |
| 40 | - unsigned access_time = access_time_1(i, j); | |
| 43 | + unsigned long long access_time = access_time_1(i, j); | |
| 41 | 44 | //unsigned overhead = 10; |
| 42 | 45 | //multiply access time by 1000 to convert to ns |
| 46 | + //double avg = (access_time * 1.111)/(MAX_ARRAY_SIZE); | |
| 43 | 47 | double avg = (access_time * 1000.0)/(MAX_ARRAY_SIZE); |
| 44 | 48 | printf("Size: %uKB access: %lluus, avg: %gns\n", i >> 10, access_time, avg); |
| 45 | 49 | } |
memory/memory_access_time.o
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b20e857