1 /* This sample demonstrates the way you can perform independed tasks
2 on the different GPUs */
3
4 // Disable some warnings which are caused with CUDA headers
5 #if defined(_MSC_VER)
6 #pragma warning(disable: 4201 4408 4100)
7 #endif
8
9 #include <iostream>
10 #include "cvconfig.h"
11 #include "opencv2/core/core.hpp"
12 #include "opencv2/cudaarithm.hpp"
13
14 #ifdef HAVE_TBB
15 # include "tbb/tbb_stddef.h"
16 # if TBB_VERSION_MAJOR*100 + TBB_VERSION_MINOR >= 202
17 # include "tbb/tbb.h"
18 # include "tbb/task.h"
19 # undef min
20 # undef max
21 # else
22 # undef HAVE_TBB
23 # endif
24 #endif
25
26 #if !defined(HAVE_CUDA) || !defined(HAVE_TBB) || defined(__arm__)
27
main()28 int main()
29 {
30 #if !defined(HAVE_CUDA)
31 std::cout << "CUDA support is required (CMake key 'WITH_CUDA' must be true).\n";
32 #endif
33
34 #if !defined(HAVE_TBB)
35 std::cout << "TBB support is required (CMake key 'WITH_TBB' must be true).\n";
36 #endif
37
38 #if defined(__arm__)
39 std::cout << "Unsupported for ARM CUDA library." << std::endl;
40 #endif
41
42 return 0;
43 }
44
45 #else
46
47 #include <cuda.h>
48 #include <cuda_runtime.h>
49
50 using namespace std;
51 using namespace cv;
52 using namespace cv::cuda;
53
54 struct Worker { void operator()(int device_id) const; };
55 void destroyContexts();
56
57 #define safeCall(expr) safeCall_(expr, #expr, __FILE__, __LINE__)
safeCall_(int code,const char * expr,const char * file,int line)58 inline void safeCall_(int code, const char* expr, const char* file, int line)
59 {
60 if (code != CUDA_SUCCESS)
61 {
62 std::cout << "CUDA driver API error: code " << code << ", expr " << expr
63 << ", file " << file << ", line " << line << endl;
64 destroyContexts();
65 exit(-1);
66 }
67 }
68
69 // Each GPU is associated with its own context
70 CUcontext contexts[2];
71
main()72 int main()
73 {
74 int num_devices = getCudaEnabledDeviceCount();
75 if (num_devices < 2)
76 {
77 std::cout << "Two or more GPUs are required\n";
78 return -1;
79 }
80
81 for (int i = 0; i < num_devices; ++i)
82 {
83 cv::cuda::printShortCudaDeviceInfo(i);
84
85 DeviceInfo dev_info(i);
86 if (!dev_info.isCompatible())
87 {
88 std::cout << "CUDA module isn't built for GPU #" << i << " ("
89 << dev_info.name() << ", CC " << dev_info.majorVersion()
90 << dev_info.minorVersion() << "\n";
91 return -1;
92 }
93 }
94
95 // Init CUDA Driver API
96 safeCall(cuInit(0));
97
98 // Create context for GPU #0
99 CUdevice device;
100 safeCall(cuDeviceGet(&device, 0));
101 safeCall(cuCtxCreate(&contexts[0], 0, device));
102
103 CUcontext prev_context;
104 safeCall(cuCtxPopCurrent(&prev_context));
105
106 // Create context for GPU #1
107 safeCall(cuDeviceGet(&device, 1));
108 safeCall(cuCtxCreate(&contexts[1], 0, device));
109
110 safeCall(cuCtxPopCurrent(&prev_context));
111
112 // Execute calculation in two threads using two GPUs
113 int devices[] = {0, 1};
114 tbb::parallel_do(devices, devices + 2, Worker());
115
116 destroyContexts();
117 return 0;
118 }
119
120
operator ()(int device_id) const121 void Worker::operator()(int device_id) const
122 {
123 // Set the proper context
124 safeCall(cuCtxPushCurrent(contexts[device_id]));
125
126 Mat src(1000, 1000, CV_32F);
127 Mat dst;
128
129 RNG rng(0);
130 rng.fill(src, RNG::UNIFORM, 0, 1);
131
132 // CPU works
133 cv::transpose(src, dst);
134
135 // GPU works
136 GpuMat d_src(src);
137 GpuMat d_dst;
138 cuda::transpose(d_src, d_dst);
139
140 // Check results
141 bool passed = cv::norm(dst - Mat(d_dst), NORM_INF) < 1e-3;
142 std::cout << "GPU #" << device_id << " (" << DeviceInfo().name() << "): "
143 << (passed ? "passed" : "FAILED") << endl;
144
145 // Deallocate data here, otherwise deallocation will be performed
146 // after context is extracted from the stack
147 d_src.release();
148 d_dst.release();
149
150 CUcontext prev_context;
151 safeCall(cuCtxPopCurrent(&prev_context));
152 }
153
154
destroyContexts()155 void destroyContexts()
156 {
157 safeCall(cuCtxDestroy(contexts[0]));
158 safeCall(cuCtxDestroy(contexts[1]));
159 }
160
161 #endif
162