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
|
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
#include <omp.h>
#include "../../support/common.h"
#include "../../support/graph.h"
#include "../../support/params.h"
#include "../../support/timer.h"
#include "../../support/utils.h"
int main(int argc, char** argv) {
// Process parameters
struct Params p = input_params(argc, argv);
// Initialize BFS data structures
PRINT_INFO(p.verbosity >= 1, "Reading graph %s", p.fileName);
struct COOGraph cooGraph = readCOOGraph(p.fileName);
PRINT_INFO(p.verbosity >= 1, " Graph has %d nodes and %d edges", cooGraph.numNodes, cooGraph.numEdges);
Timer timer;
for(int rep = 0; rep < 100; rep++) {
struct CSRGraph csrGraph = coo2csr(cooGraph);
uint32_t* nodeLevel = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
uint32_t* nodeLevelRef = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
for(uint32_t i = 0; i < csrGraph.numNodes; ++i) {
nodeLevel[i] = UINT32_MAX; // Unreachable
nodeLevelRef[i] = UINT32_MAX; // Unreachable
}
uint32_t srcNode = 0;
// Initialize frontier double buffers
uint32_t* buffer1 = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
uint32_t* buffer2 = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
uint32_t* prevFrontier = buffer1;
uint32_t* currFrontier = buffer2;
// Calculating result on CPU
startTimer(&timer, 0, 0);
nodeLevel[srcNode] = 0;
prevFrontier[0] = srcNode;
uint32_t numPrevFrontier = 1;
for(uint32_t level = 1; numPrevFrontier > 0; ++level) {
uint32_t numCurrFrontier = 0;
// Visit nodes in the previous frontier
#pragma omp parallel for
for(uint32_t i = 0; i < numPrevFrontier; ++i) {
uint32_t node = prevFrontier[i];
for(uint32_t edge = csrGraph.nodePtrs[node]; edge < csrGraph.nodePtrs[node + 1]; ++edge) {
uint32_t neighbor = csrGraph.neighborIdxs[edge];
uint32_t justVisited = 0;
#pragma omp critical
{
if(nodeLevel[neighbor] == UINT32_MAX) { // Node not previously visited
nodeLevel[neighbor] = level;
justVisited = 1;
}
}
if(justVisited) {
uint32_t currFrontierIdx;
#pragma omp critical
{
currFrontierIdx = numCurrFrontier++;
}
currFrontier[currFrontierIdx] = neighbor;
}
}
}
// Swap buffers
uint32_t* tmp = prevFrontier;
prevFrontier = currFrontier;
currFrontier = tmp;
numPrevFrontier = numCurrFrontier;
}
stopTimer(&timer, 0);
freeCSRGraph(csrGraph);
free(buffer1);
free(buffer2);
csrGraph = coo2csr(cooGraph);
srcNode = 0;
// Initialize frontier double buffers
buffer1 = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
buffer2 = (uint32_t*) malloc(csrGraph.numNodes*sizeof(uint32_t));
prevFrontier = buffer1;
currFrontier = buffer2;
// Calculating result on CPU sequentially
startTimer(&timer, 1, 0);
nodeLevelRef[srcNode] = 0;
prevFrontier[0] = srcNode;
numPrevFrontier = 1;
for(uint32_t level = 1; numPrevFrontier > 0; ++level) {
uint32_t numCurrFrontier = 0;
// Visit nodes in the previous frontier
for(uint32_t i = 0; i < numPrevFrontier; ++i) {
uint32_t node = prevFrontier[i];
for(uint32_t edge = csrGraph.nodePtrs[node]; edge < csrGraph.nodePtrs[node + 1]; ++edge) {
uint32_t neighbor = csrGraph.neighborIdxs[edge];
uint32_t justVisited = 0;
if(nodeLevelRef[neighbor] == UINT32_MAX) { // Node not previously visited
nodeLevelRef[neighbor] = level;
justVisited = 1;
}
if(justVisited) {
uint32_t currFrontierIdx;
currFrontierIdx = numCurrFrontier++;
currFrontier[currFrontierIdx] = neighbor;
}
}
}
// Swap buffers
uint32_t* tmp = prevFrontier;
prevFrontier = currFrontier;
currFrontier = tmp;
numPrevFrontier = numCurrFrontier;
}
stopTimer(&timer, 1);
unsigned int nr_threads = 0;
#pragma omp parallel
#pragma omp atomic
nr_threads++;
// Verifying result
int isOK = 1;
for(uint32_t nodeIdx = 0; nodeIdx < csrGraph.numNodes; ++nodeIdx) {
if(nodeLevel[nodeIdx] != nodeLevelRef[nodeIdx]) {
PRINT_ERROR("Mismatch at node %u (CPU sequential result = level %u, CPU parallel result = level %u)", nodeIdx, nodeLevelRef[nodeIdx], nodeLevel[nodeIdx]);
isOK = 0;
}
}
if (isOK) {
printf("[::] BFS CPU | n_threads=%d e_type=%s n_elements=%d "
"| throughput_seq_MBps=%f throughput_MBps=%f",
nr_threads, "uint32_t", csrGraph.numNodes,
csrGraph.numNodes * sizeof(uint32_t) / timer.time[1],
csrGraph.numNodes * sizeof(uint32_t) / timer.time[0]);
printf(" throughput_seq_MOpps=%f throughput_MOpps=%f",
csrGraph.numNodes / timer.time[1],
csrGraph.numNodes / timer.time[0]);
printAll(&timer, 1);
}
freeCSRGraph(csrGraph);
free(nodeLevel);
free(nodeLevelRef);
free(buffer1);
free(buffer2);
}
// Deallocate data structures
freeCOOGraph(cooGraph);
return 0;
}
|
