Valgrind和CUDA:所报告的泄漏是否真实? [英] Valgrind and CUDA: Are reported leaks real?
问题描述
我的应用程序中有一个非常简单的CUDA组件. Valgrind报告了很多泄漏和仍可到达的事件，所有这些都与cudaMalloc调用有关.
I have a very simple CUDA component in my application. Valgrind reports a lot of leaks and still-reachables, all related to the cudaMalloc calls.
这些泄漏真的吗?我为每个cudaMalloc调用cudaFree.此valgrind是否无法解释GPU内存分配?如果这些泄漏不是真的，我可以抑制它们，让valgrind仅分析应用程序的非gpu部分吗?
Are these leaks real? I call cudaFree for every cudaMalloc. Is this valgrind's inability to interpret GPU memory allocation? If these leaks are not real, can I suppress them and have valgrind only analyse the non-gpu part of the application?
extern "C"
unsigned int *gethash(int nodec, char *h_nodev, int len) {
unsigned int *h_out = (unsigned int *)malloc(sizeof(unsigned int) * nodec);
char *d_in;
unsigned int *d_out;
cudaMalloc((void**) &d_in, sizeof(char) * len * nodec);
cudaMalloc((void**) &d_out, sizeof(unsigned int) * nodec);
cudaMemcpy(d_in, h_nodev, sizeof(char) * len * nodec, cudaMemcpyHostToDevice);
int blocks = 1 + nodec / 512;
cube<<<blocks, 512>>>(d_out, d_in, nodec, len);
cudaMemcpy(h_out, d_out, sizeof(unsigned int) * nodec, cudaMemcpyDeviceToHost);
cudaFree(d_in);
cudaFree(d_out);
return h_out;
}
Valgrind输出的最后一位:
Last bit of the Valgrind output:
...
==5727== 5,468 (5,020 direct, 448 indirect) bytes in 1 blocks are definitely lost in loss record 506 of 523
==5727== at 0x402B965: calloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==5727== by 0x4843910: ??? (in /usr/lib/nvidia-319-updates/libcuda.so.319.60)
==5727== by 0x48403E9: ??? (in /usr/lib/nvidia-319-updates/libcuda.so.319.60)
==5727== by 0x498B32D: ??? (in /usr/lib/nvidia-319-updates/libcuda.so.319.60)
==5727== by 0x494A6E4: ??? (in /usr/lib/nvidia-319-updates/libcuda.so.319.60)
==5727== by 0x4849534: ??? (in /usr/lib/nvidia-319-updates/libcuda.so.319.60)
==5727== by 0x48191DD: cuInit (in /usr/lib/nvidia-319-updates/libcuda.so.319.60)
==5727== by 0x406B4D6: ??? (in /usr/lib/i386-linux-gnu/libcudart.so.5.0.35)
==5727== by 0x406B61F: ??? (in /usr/lib/i386-linux-gnu/libcudart.so.5.0.35)
==5727== by 0x408695D: cudaMalloc (in /usr/lib/i386-linux-gnu/libcudart.so.5.0.35)
==5727== by 0x804A006: gethash (hashkernel.cu:36)
==5727== by 0x804905F: chkisomorphs (bdd.c:326)
==5727==
==5727== LEAK SUMMARY:
==5727== definitely lost: 10,240 bytes in 6 blocks
==5727== indirectly lost: 1,505 bytes in 54 blocks
==5727== possibly lost: 7,972 bytes in 104 blocks
==5727== still reachable: 626,997 bytes in 1,201 blocks
==5727== suppressed: 0 bytes in 0 blocks
推荐答案
这是一个已知的问题，valgrind报告了一堆CUDA内容的假阳性.避免看到它的最佳方法是使用valgrind抑制，您可以在此处阅读全部内容: http://valgrind.org/docs/manual/manual-core.html#manual- core.suppress
It's a known issue that valgrind reports false-positives for a bunch of CUDA stuff. The best way to avoid seeing it would be to use valgrind suppressions, which you can read all about here: http://valgrind.org/docs/manual/manual-core.html#manual-core.suppress
如果您想快速入门一些更接近您的特定问题的东西，可以在Nvidia开发论坛上发表一篇有趣的文章.它具有指向样本抑制规则文件的链接. https://devtalk.nvidia.com/default/topic /404607/valgrind-3-4-suppressions-a-little-howto/
If you want to jumpstart into something a little closer to your specific issue, an interesting post is this one on the Nvidia dev forums. It has a link to a sample suppression rule file. https://devtalk.nvidia.com/default/topic/404607/valgrind-3-4-suppressions-a-little-howto/
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