CMake 无法正确找到 CUDA 库

Question

我正在尝试构建一个需要 CUDA 的程序。对于我提供的 CMake 脚本：

cmake -D CUDA_TOOLKIT_ROOT_DIR=/usr/local/cuda ..

找到CUDA，CMake运行正常：

staudt ~/workspace/clutbb/cluster/build $ cmake -D CUDA_TOOLKIT_ROOT_DIR=/usr/local/cuda ..                                                                                  
-- Found CUDA: /usr/local/cuda (found version "6.5") 
-- Found Intel TBB
-- Boost version: 1.56.0
-- Found the following Boost libraries:
--   iostreams
--   program_options
-- Looking for include file pthread.h
-- Looking for include file pthread.h - found
-- Looking for pthread_create
-- Looking for pthread_create - not found
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE  
-- Could NOT find SDL (missing:  SDL_LIBRARY SDL_INCLUDE_DIR) 
-- Configuring done
-- Generating done
-- Build files have been written to: /home/i11/staudt/workspace/clutbb/cluster/build

但随后链接器步骤失败：

staudt ~/workspace/clutbb/cluster/build $ make
[ 69%] Built target cluster
Linking CXX executable clu
CMakeFiles/clu.dir/clu.cpp.o: In function `initCUDA(int&, CUctx_st*&, int const&)':
clu.cpp:(.text+0x517): undefined reference to `cuInit'
clu.cpp:(.text+0x52b): undefined reference to `cuDeviceGet'
clu.cpp:(.text+0x53f): undefined reference to `cuCtxCreate_v2'
clu.cpp:(.text+0x559): undefined reference to `cuDeviceGetName'
clu.cpp:(.text+0x55e): undefined reference to `cuCtxSynchronize'
CMakeFiles/clu.dir/clu.cpp.o: In function `exitCUDA(int&, CUctx_st*&)':
clu.cpp:(.text+0x684): undefined reference to `cuCtxDestroy_v2'
CMakeFiles/clu.dir/clu.cpp.o: In function `main':
clu.cpp:(.text.startup+0x1092): undefined reference to `cuCtxDestroy_v2'
clu.cpp:(.text.startup+0x10d1): undefined reference to `cuCtxSynchronize'
clu.cpp:(.text.startup+0x10e1): undefined reference to `cuCtxSynchronize'
collect2: error: ld returned 1 exit status
make[2]: *** [bin/clu] Fehler 1
make[1]: *** [bin/CMakeFiles/clu.dir/all] Fehler 2
make: *** [all] Fehler 2

所需的库位于/usr/local/cuda/lib64/stubs/libcuda.so，但我如何将其指出给 cmake 或 make？

Answer 1

在您现在发布的存档中，有多个项目层次结构。您在问题中发布的实际错误是在 clutbb/cluster/bin 目录中基于 clu.cpp 的 clu 项目的编译和链接过程中发生的。

在同一目录下，有一个 CMakeLists.txt 文件。此文件管理项目层次结构的这一特定级别。

在这个特定的 CMakeLists.txt 文件中，有以下部分：

cuda_add_executable(clu clu.cpp)
target_link_libraries(clu ${CUDA_LIBRARY} ${TBB_LIBRARY} ${Boost_LIBRARIES} rt)
target_link_libraries(clu cluster)

尝试将上面的中间行修改为：

target_link_libraries(clu ${CUDA_LIBRARY} ${TBB_LIBRARY} ${Boost_LIBRARIES} rt cuda)

这应该可以修复链接器命令行中缺少的-lcuda。可能仍然需要在您的计算机上为其提供指向 libcuda.so 的路径，但可能没有必要，具体取决于您的计算机环境的设置方式。

Answer 2

在 CMake 3.17+ 上执行此操作的正确方法是使用 FindCUDAToolkit 模块，如下所示：

find_package(CUDAToolkit REQUIRED)
target_link_libraries(my_target PRIVATE CUDA::cudart CUDA::cuda_driver)

CUDA::cuda_driver 目标等同于 -lcuda，当链接器可以找到它时，它是指向正确库的绝对路径。您应该避免通过target_link_libraries 添加系统库以确保可移植性。

---

如果您有旧版本（CMake 3.0+），您可以使用（现已弃用）FindCUDA 模块来模仿 3.17 模块，如下所示：

find_package(CUDA REQUIRED)

# Do what the new package does
find_library(CUDA_DRIVER_LIBRARY
             NAMES cuda_driver cuda
             HINTS ${CUDA_TOOLKIT_ROOT_DIR}
                   ENV CUDA_PATH
             PATH_SUFFIXES nvidia/current lib64 lib/x64 lib)
if (NOT CUDA_DRIVER_LIBRARY)
    # Don't try any stub directories until we have exhausted all other search locations.
    find_library(CUDA_DRIVER_LIBRARY
                 NAMES cuda_driver cuda
                 HINTS ${CUDA_TOOLKIT_ROOT_DIR}
                       ENV CUDA_PATH
                 PATH_SUFFIXES lib64/stubs lib/x64/stubs lib/stubs stubs)
endif ()
mark_as_advanced(CUDA_DRIVER_LIBRARY)
##

target_include_directories(my_target PRIVATE ${CUDA_INCLUDE_DIRS})
target_link_libraries(my_target PRIVATE ${CUDA_LIBRARIES} ${CUDA_DRIVER_LIBRARY})

This is adapted from the official sources, here.

Answer 3

带有主机调用的 C++ 文件不知道它需要链接到 libcudart。您必须为该文件所在的文件/二进制文件显式设置依赖关系，例如。

target_link_libraries(clu ${CUDA_LIBRARIES})

以上回复略有错误。无论出于何种原因，似乎 libcuda.so 都安装在了意外的位置。您可以尝试将CMAKE_LIBRARY_PATH 或/和CUDA_LIB_PATH 设置为该路径。

我认为 CUDA_LIB_PATH 需要在 cmake 之外设置，例如export CUDA_LIB_PATH=/usr/local/cuda/lib64/stubs/