问题描述
我尝试以并行模式运行LIBSVM，但我的问题是在OpenMP中。根据，我已经修改了#pragma调用的代码使用OpenMP。我还通过添加一个-fopenmp参数修改了Makefile（对于un * x）：
I am trying to run LIBSVM in parallel mode, however my question is in OpenMP in general. According to LIBSVM FAQ, I have modified the code with #pragma calls to use OpenMP. I also modified the Makefile (for un*x) by adding a -fopenmp argument so it becomes:
CFLAGS = -Wall -Wconversion -O3 -fPIC -fopenmp
代码编译良好。我检查（因为它不是我的电脑）OpenMP是否安装：
The code compiles well. I check (since it's not my PC) whether OpenMP is installed by :
/sbin/ldconfig -p | grep gomp
，并看到它可能安装：
libgomp.so.1 (libc6,x86-64) => /usr/lib64/libgomp.so.1
libgomp.so.1 (libc6) => /usr/lib/libgomp.so.1
当我运行程序，我没有看到任何速度的改进。此外，当我检查顶的过程是使用最多％100 CPU（有8个核心），也没有CPU瓶颈（只有一个更多的用户与％100 CPU使用），我期待看到超过
Now; when I run the program, I don't see any speed improvements. Also when I check with "top" the process is using at most %100 CPU (there are 8 cores), also there is not a CPU bottleneck (only one more user with %100 CPU usage), I was expecting to see more than %100 (or a different indicator) that process is using multiple cores.
有没有办法检查它是否正在使用多个核心？
Is there a way to check that it is working multiple core?
推荐答案
您可以使用函数 omp_get_num_threads（）。它将返回您的程序使用的线程数。
You can use the function omp_get_num_threads(). It will return you the number of threads that are used by your program.
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