cuda::StereoBM - fix hanging and racing issue

- Fix hanging issue on 2080 Ti
- Fix racing issue
pull/13850/head
Namgoo Lee 6 years ago
parent b12e1acdec
commit 1a961660d8
  1. 77
      modules/cudastereo/src/cuda/stereobm.cu

@ -71,48 +71,54 @@ namespace cv { namespace cuda { namespace device
}
template<int RADIUS>
__device__ unsigned int CalcSSD(volatile unsigned int *col_ssd_cache, volatile unsigned int *col_ssd)
__device__ unsigned int CalcSSD(volatile unsigned int *col_ssd_cache, volatile unsigned int *col_ssd, const int X)
{
unsigned int cache = 0;
unsigned int cache2 = 0;
if (X < cwidth - RADIUS)
{
for(int i = 1; i <= RADIUS; i++)
cache += col_ssd[i];
col_ssd_cache[0] = cache;
}
__syncthreads();
if (X < cwidth - RADIUS)
{
if (threadIdx.x < BLOCK_W - RADIUS)
cache2 = col_ssd_cache[RADIUS];
else
for(int i = RADIUS + 1; i < (2 * RADIUS + 1); i++)
cache2 += col_ssd[i];
}
return col_ssd[0] + cache + cache2;
}
template<int RADIUS>
__device__ uint2 MinSSD(volatile unsigned int *col_ssd_cache, volatile unsigned int *col_ssd)
__device__ uint2 MinSSD(volatile unsigned int *col_ssd_cache, volatile unsigned int *col_ssd, const int X)
{
unsigned int ssd[N_DISPARITIES];
//See above: #define COL_SSD_SIZE (BLOCK_W + 2 * RADIUS)
ssd[0] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 0 * (BLOCK_W + 2 * RADIUS));
ssd[0] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 0 * (BLOCK_W + 2 * RADIUS), X);
__syncthreads();
ssd[1] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 1 * (BLOCK_W + 2 * RADIUS));
ssd[1] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 1 * (BLOCK_W + 2 * RADIUS), X);
__syncthreads();
ssd[2] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 2 * (BLOCK_W + 2 * RADIUS));
ssd[2] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 2 * (BLOCK_W + 2 * RADIUS), X);
__syncthreads();
ssd[3] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 3 * (BLOCK_W + 2 * RADIUS));
ssd[3] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 3 * (BLOCK_W + 2 * RADIUS), X);
__syncthreads();
ssd[4] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 4 * (BLOCK_W + 2 * RADIUS));
ssd[4] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 4 * (BLOCK_W + 2 * RADIUS), X);
__syncthreads();
ssd[5] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 5 * (BLOCK_W + 2 * RADIUS));
ssd[5] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 5 * (BLOCK_W + 2 * RADIUS), X);
__syncthreads();
ssd[6] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 6 * (BLOCK_W + 2 * RADIUS));
ssd[6] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 6 * (BLOCK_W + 2 * RADIUS), X);
__syncthreads();
ssd[7] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 7 * (BLOCK_W + 2 * RADIUS));
ssd[7] = CalcSSD<RADIUS>(col_ssd_cache, col_ssd + 7 * (BLOCK_W + 2 * RADIUS), X);
int mssd = ::min(::min(::min(ssd[0], ssd[1]), ::min(ssd[4], ssd[5])), ::min(::min(ssd[2], ssd[3]), ::min(ssd[6], ssd[7])));
@ -243,12 +249,12 @@ namespace cv { namespace cuda { namespace device
unsigned int* minSSDImage = cminSSDImage + X + Y * cminSSD_step;
unsigned char* disparImage = disp.data + X + Y * disp.step;
/* if (X < cwidth)
{
unsigned int *minSSDImage_end = minSSDImage + min(ROWSperTHREAD, cheight - Y) * minssd_step;
for(uint *ptr = minSSDImage; ptr != minSSDImage_end; ptr += minssd_step )
*ptr = 0xFFFFFFFF;
}*/
//if (X < cwidth)
//{
// unsigned int *minSSDImage_end = minSSDImage + min(ROWSperTHREAD, cheight - Y) * minssd_step;
// for(uint *ptr = minSSDImage; ptr != minSSDImage_end; ptr += minssd_step )
// *ptr = 0xFFFFFFFF;
//}
int end_row = ::min(ROWSperTHREAD, cheight - Y - RADIUS);
int y_tex;
int x_tex = X - RADIUS;
@ -268,15 +274,29 @@ namespace cv { namespace cuda { namespace device
__syncthreads(); //before MinSSD function
if (X < cwidth - RADIUS && Y < cheight - RADIUS)
if (Y < cheight - RADIUS)
{
uint2 minSSD = MinSSD<RADIUS>(col_ssd_cache + threadIdx.x, col_ssd, X);
// For threads that do not satisfy the if condition below("X < cwidth - RADIUS"), previously
// computed "minSSD" value, which is the result of "MinSSD" function call, is not used at all.
//
// However, since the "MinSSD" function has "__syncthreads" call in its body, those threads
// must also call "MinSSD" to avoid deadlock. (#13850)
//
// From CUDA 9, using "__syncwarp" with proper mask value instead of using "__syncthreads"
// could be an option, but the shared memory access pattern does not allow this option,
// resulting in race condition. (Checked via "cuda-memcheck --tool racecheck")
if (X < cwidth - RADIUS)
{
uint2 minSSD = MinSSD<RADIUS>(col_ssd_cache + threadIdx.x, col_ssd);
if (minSSD.x < minSSDImage[0])
{
disparImage[0] = (unsigned char)(d + minSSD.y);
minSSDImage[0] = minSSD.x;
}
}
}
for(int row = 1; row < end_row; row++)
{
@ -295,17 +315,34 @@ namespace cv { namespace cuda { namespace device
__syncthreads(); //before MinSSD function
if (X < cwidth - RADIUS && row < cheight - RADIUS - Y)
if (row < cheight - RADIUS - Y)
{
uint2 minSSD = MinSSD<RADIUS>(col_ssd_cache + threadIdx.x, col_ssd, X);
// For threads that do not satisfy the if condition below("X < cwidth - RADIUS"), previously
// computed "minSSD" value, which is the result of "MinSSD" function call, is not used at all.
//
// However, since the "MinSSD" function has "__syncthreads" call in its body, those threads
// must also call "MinSSD" to avoid deadlock. (#13850)
//
// From CUDA 9, using "__syncwarp" with proper mask value instead of using "__syncthreads"
// could be an option, but the shared memory access pattern does not allow this option,
// resulting in race condition. (Checked via "cuda-memcheck --tool racecheck")
if (X < cwidth - RADIUS)
{
int idx = row * cminSSD_step;
uint2 minSSD = MinSSD<RADIUS>(col_ssd_cache + threadIdx.x, col_ssd);
if (minSSD.x < minSSDImage[idx])
{
disparImage[disp.step * row] = (unsigned char)(d + minSSD.y);
minSSDImage[idx] = minSSD.x;
}
}
}
} // for row loop
__syncthreads(); // before initializing shared memory at the beginning of next loop
} // for d loop
}

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