CUDA 错误消息：未指定的启动失败
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【中文标题】CUDA 错误消息：未指定的启动失败【英文标题】：CUDA error message : unspecified launch failure 【发布时间】：2012-04-11 17:00:03 【问题描述】：这是我的 CUDA 代码的一部分。但是这段代码的最后一部分显示了一些错误信息。
unsigned int *mat_count;
off_t *mat_position;
unsigned int *matches_count;
off_t *matches_position;
......
cudaMalloc ( (void **) &mat_count, sizeof(unsigned int)*10);
cudaMalloc ( (void **) &mat_position, sizeof(off_t)*10);
......
matches_count = (unsigned int *)malloc(sizeof(unsigned int)*10);
matches_position = (off_t *)malloc(sizeof(off_t)*10);
for ( i = 0 ; i < 10 ; i++ )
matches_count [i] = 0;
matches_position[i] = 0;
......
cudaMemcpy (mat_count, matches_count , sizeof(unsigned int)*10, cudaMemcpyHostToDevice );
cudaMemcpy (mat_position, matches_position, sizeof(off_t)*10, cudaMemcpyHostToDevice );
......
match<<<BLK_SIZE,THR_SIZE>>>(
reference_total,
indextable_total,
sequences,
start_sequence,
sequence_length,
end_sequence,
ref_base,
idx_base,
msk_base,
mat_count,
mat_position,
reference,
first_indexes,
seqmaskc
);
err=cudaGetLastError();
if(err!=cudaSuccess)
printf("\n1 %s\n", cudaGetErrorString(err));
err= cudaMemcpy (matches_count , mat_count, sizeof(unsigned int)*10, cudaMemcpyDeviceToHost );
if(err!=cudaSuccess)
printf("\n2 %s\n", cudaGetErrorString(err));
err= cudaMemcpy (matches_position, mat_position, sizeof(off_t)*10, cudaMemcpyDeviceToHost );
if(err!=cudaSuccess)
printf("\n3 %s\n", cudaGetErrorString(err));
以下部分代码曾报告“未指定的启动失败”此错误消息。 不知道为什么会报这个错误信息。
err=cudaMemcpy (matches_position, mat_position, sizeof(off_t)*10, cudaMemcpyDeviceToHost );
if(err!=cudaSuccess)
printf("\n3 %s\n", cudaGetErrorString(err));
以下是匹配功能的一部分。
__global__ void match(...)
......
reference_blk = (THR_SIZE * blockIdx.x + threadIdx.x) * 32 + reference;
......
//-- added for parallize --//
for (p = start_p ; p != last_p ; p++)
for ( s = start_sequence, sequence = sequences ; s != end_sequence ;
s++, sequence += sequence_bytes )
ref_off = *(((unsigned int*)(idx_base)) + p);
shifted_in = 0;
if((int)(first_indexes[s-start_sequence] % 8 - ref_off % 8) < 0)
int shamt2 = (ref_off % 8 - first_indexes[s-start_sequence] % 8);
mask_buffer = *((unsigned long *)(msk_base + (ref_off - first_indexes[s-start_sequence])/8)) >> shamt2;
if( ( (*(unsigned long *)(seqmaskc + 16 * (s-start_sequence))) ^ mask_buffer ) << shamt2) continue;
else if((int)(first_indexes[s-start_sequence] % 8 - ref_off % 8) == 0)
mask_buffer = *((unsigned long *)(msk_base + (ref_off)/8));
if( (*(unsigned long *)(seqmaskc + 16 * (s-start_sequence)) ^ mask_buffer)) continue;
else
int shamt2 = 8 - (first_indexes[s-start_sequence] % 8 - ref_off % 8);
mask_buffer = *((unsigned long *)(msk_base + (ref_off/8- first_indexes[s-start_sequence]/8) - 1)) >> shamt2;
if( ( (*(unsigned long *)(seqmaskc + 16 * (s-start_sequence))) ^ mask_buffer ) << shamt2) continue;
//full compare
if((int)(first_indexes[s-start_sequence] % 4 - ref_off % 4) < 0)
int shamt = (ref_off % 4 - first_indexes[s-start_sequence] % 4) * 2;
memcpy(reference_blk, ref_base + ref_off / 4 - first_indexes[s-start_sequence] / 4, sequence_bytes);
......
//-- instead of memcmp --//
int v = 0;
char *p1 = (char *)sequence;
char *p2 = (char *)reference_blk;
int tmp_asd = sequence_bytes;
while(tmp_asd!=0)
v = *(p1++) - *(p2++);
if(v!=0)
break;
tmp_asd--;
if(v == 0)
mat_count[s - (int)start_sequence]++; /* Maintain count */
mat_position[s - (int)start_sequence] = ref_off-first_indexes[s-start_sequence]; /* Record latest position */
else if((int)(first_indexes[s-start_sequence] % 4 - ref_off % 4 )== 0)
memcpy(reference_blk, ref_base + ref_off / 4 - first_indexes[s-start_sequence] / 4, sequence_bytes);
.......
//-- instead of memcmp --//
int v = 0;
char *p1 = (char *)sequence;
char *p2 = (char *)reference_blk;
int tmp_asd = sequence_bytes;
while(tmp_asd!=0)
v = *(p1++) - *(p2++);
if(v!=0)
break;
tmp_asd--;
if(v == 0)
mat_count[s - (int)start_sequence]++; /* Maintain count */
mat_position[s - (int)start_sequence] = ref_off-first_indexes[s-start_sequence]; /* Record latest position */
else
int shamt = 8 - (first_indexes[s-start_sequence] % 4 - ref_off % 4) * 2;
memcpy(reference_blk, ref_base + ref_off / 4 - first_indexes[s-start_sequence] / 4 - 1, 32);
......
//-- instead of memcmp --//
int v = 0;
char *p1 = (char *)sequence;
char *p2 = (char *)reference_blk;
int tmp_asd = sequence_bytes;
while(tmp_asd!=0)
v = *(p1++) - *(p2++);
if(v!=0)
break;
tmp_asd--;
if (v == 0)
mat_count[s - (int)start_sequence]++; /* Maintain count */
mat_position[s - (int)start_sequence] = ref_off-first_indexes[s-start_sequence];/* Record latest position */
【问题讨论】：
BLK_SIZE 和 THR_SIZE 的值是多少？
BLK_SIZE 和 THR_SIZE 为一。
你可能需要贴出内核函数match的代码
这意味着你有内存冲突。在调试器或内存检查器下运行。
您是否检查过您计算的众多偏移量是否有效？尤其是在调用 memcpy() 时？
【参考方案1】：
未指定的启动失败几乎总是一个段错误。您的内核中某处出现索引错误，可能是在访问全局内存时。
我会查看您的代码，但有点难以理解...
【讨论】：
【参考方案2】：使用调试标志nvcc -G -g 编译您的应用程序，并尝试在cuda-memcheck 或cuda-gdb 中运行您的应用程序。它可能会提示您问题可能出在哪里。
快跑
cuda-memcheck ./yourApp
【讨论】：
【参考方案3】：对我来说，由于nvcc 未检测到无限递归，CUDA 正在生成“未指定的启动失败”。代码做的很简单：
int f()
return f();
cuda-gdb 中的回溯显示了一些任意代码，而不是错误的来源。
【讨论】：
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