Question

我有一个由3个CUDA文件和2个标题组成的简单脚本： main.cu ， kernel.cu func.cu ，< em> kernel.h 和 func.h 。他们的目标是计算2个向量的总和。

// main.cu
#include <stdio.h>
#include <stdlib.h>
#include <cuda_runtime.h>
#include <cuda.h>

#include "kernel.h"

int main(){
/* Error code to check return values for CUDA calls */
cudaError_t err = cudaSuccess;   

srand(time(NULL));
int count = 100;
int A[count], B[count];
int *h_A, *h_B;
h_A = A; h_B = B;

int i;
for(i=0;i<count;i++){
    *(h_A+i) = rand() % count; /* Oppure: h_A[i] = rand() % count; */
    *(h_B+i) = rand() % count; /* Oppure: h_B[i] = rand() % count; */
}
/* Display dei vettori A e B. */
printf("\nPrimi cinque valori di A = ");
for(i=0;i<4;i++){printf("%d ", A[i]);}
printf("\nPrimi cinque valori di B = ");
for(i=0;i<4;i++){printf("%d ", B[i]);}


int *d_A, *d_B;

err = cudaMalloc((void**)&d_A, count*sizeof(int));
if (err != cudaSuccess){fprintf(stderr, "Failed to allocate device vector A (error code %s)! \n", cudaGetErrorString(err));exit(EXIT_FAILURE);}
err = cudaMalloc((void**)&d_B, count*sizeof(int));
if (err != cudaSuccess){fprintf(stderr, "Failed to allocate device vector A (error code %s)! \n", cudaGetErrorString(err));exit(EXIT_FAILURE);}

err = cudaMemcpy(d_A, A, count*sizeof(int), cudaMemcpyHostToDevice);
if (err != cudaSuccess){fprintf(stderr, "Failed to copy vector A from host to device (error code %s)!\n", cudaGetErrorString(err));exit(EXIT_FAILURE);}
err = cudaMemcpy(d_B, B, count*sizeof(int), cudaMemcpyHostToDevice);
if (err != cudaSuccess){fprintf(stderr, "Failed to copy vector A from host to device (error code %s)!\n", cudaGetErrorString(err));exit(EXIT_FAILURE);}


int numThreads = 256;
int numBlocks = count/numThreads + 1;
AddInts<<<numBlocks,numThreads>>>(d_A,d_B); err = cudaGetLastError(); 

err = cudaMemcpy(A, d_A, count*sizeof(int), cudaMemcpyDeviceToHost);
if (err != cudaSuccess){fprintf(stderr, "Failed to copy vector C from device to host (error code %s)!\n", cudaGetErrorString(err));exit(EXIT_FAILURE);}

err = cudaFree(d_A); 
if (err != cudaSuccess){fprintf(stderr, "Failed to free device vector A (error code %s)!\n", cudaGetErrorString(err));exit(EXIT_FAILURE);}
err = cudaFree(d_B); 
if (err != cudaSuccess){fprintf(stderr, "Failed to free device vector A (error code %s)!\n", cudaGetErrorString(err));exit(EXIT_FAILURE);}

printf("\nPrimi cinque valori di A = ");
for(i=0;i<4;i++){printf("%d ", A[i]);}

printf("\n");
return 0;}

这里有 kernel.cu 文件：

// kernel.cu
#include "func.h"
#include "kernel.h"

__global__ void AddInts(int *a, int *b){
           int ID = get_global_index();
           *(a+ID) += *(b+ID);

}

这是 func.cu

// func.cu
#include "func.h"
__device__ int get_global_index(){
return (blockIdx.x * blockDim.x) + threadIdx.x;
}

这是 kernel.h

// kernel.h
__global__ void AddInts(int *a, int *b);

这是func.h

// func.h
__device__ int get_global_index();

我100％确定 main.cu 脚本是正确的;我也知道我可以直接在主脚本中添加内核，但这不是我测试的意图;我也知道我可以摆脱__device__函数并将其直接放在__global__内部，但这也不是我的意图。

现在问题出在这里：我写了一个非常简单的makefile，应该能够编译程序，但不知怎的，它不起作用;这是makefile：

# Location of the CUDA Toolkit
CUDA_PATH       ?= /usr/local/cuda-6.5

OSUPPER = $(shell uname -s 2>/dev/null | tr "[:lower:]" "[:upper:]")
OSLOWER = $(shell uname -s 2>/dev/null | tr "[:upper:]" "[:lower:]")

OS_SIZE    = $(shell uname -m | sed -e "s/x86_64/64/" -e "s/armv7l/32/" -e "s/aarch64/64/")
OS_ARCH    = $(shell uname -m)
ARCH_FLAGS =

DARWIN = $(strip $(findstring DARWIN, $(OSUPPER)))
ifneq ($(DARWIN),)
XCODE_GE_5 = $(shell expr `xcodebuild -version | grep -i xcode | awk '{print $$2}' | cut -d'.' -f1` \>= 5)
endif

# Take command line flags that override any of these settings
ifeq ($(x86_64),1)
OS_SIZE = 64
OS_ARCH = x86_64
endif
ifeq ($(ARMv7),1)
OS_SIZE    = 32
OS_ARCH    = armv7l
ARCH_FLAGS = -target-cpu-arch ARM
endif
ifeq ($(aarch64),1)
OS_SIZE    = 64
OS_ARCH    = aarch64
ARCH_FLAGS = -target-cpu-arch ARM
endif

# Common binaries
ifneq ($(DARWIN),)
ifeq ($(XCODE_GE_5),1)
GCC ?= clang
else
GCC ?= g++
endif
else
ifeq ($(ARMv7),1)
GCC ?= arm-linux-gnueabihf-g++
else
GCC ?= g++
endif
endif
NVCC := $(CUDA_PATH)/bin/nvcc -ccbin $(GCC)

# internal flags
NVCCFLAGS   := -m${OS_SIZE} ${ARCH_FLAGS} 
CCFLAGS     :=
LDFLAGS     :=

# Extra user flags
EXTRA_NVCCFLAGS   ?=
EXTRA_LDFLAGS     ?=
EXTRA_CCFLAGS     ?=

# OS-specific build flags
ifneq ($(DARWIN),)
LDFLAGS += -rpath $(CUDA_PATH)/lib
CCFLAGS += -arch $(OS_ARCH)
else
ifeq ($(OS_ARCH),armv7l)
ifeq ($(abi),androideabi)
  NVCCFLAGS += -target-os-variant Android
else
  ifeq ($(abi),gnueabi)
    CCFLAGS += -mfloat-abi=softfp
  else
    # default to gnueabihf
    override abi := gnueabihf
    LDFLAGS += --dynamic-linker=/lib/ld-linux-armhf.so.3
    CCFLAGS += -mfloat-abi=hard
  endif
endif
endif
endif

ifeq ($(ARMv7),1)
ifneq ($(TARGET_FS),)
GCCVERSIONLTEQ46 := $(shell expr `$(GCC) -dumpversion` \<= 4.6)
ifeq ($(GCCVERSIONLTEQ46),1)
CCFLAGS += --sysroot=$(TARGET_FS)
endif
LDFLAGS += --sysroot=$(TARGET_FS)
LDFLAGS += -rpath-link=$(TARGET_FS)/lib
LDFLAGS += -rpath-link=$(TARGET_FS)/usr/lib
LDFLAGS += -rpath-link=$(TARGET_FS)/usr/lib/arm-linux-$(abi)
endif
endif

# Debug build flags
ifeq ($(dbg),1)
  NVCCFLAGS += -g -G 
  TARGET := debug
else
  TARGET := release
endif

ALL_CCFLAGS :=
ALL_CCFLAGS += $(NVCCFLAGS)
ALL_CCFLAGS += $(EXTRA_NVCCFLAGS)
ALL_CCFLAGS += $(addprefix -Xcompiler ,$(CCFLAGS))
ALL_CCFLAGS += $(addprefix -Xcompiler ,$(EXTRA_CCFLAGS))

ALL_LDFLAGS :=
ALL_LDFLAGS += $(ALL_CCFLAGS)
ALL_LDFLAGS += $(addprefix -Xlinker ,$(LDFLAGS))
ALL_LDFLAGS += $(addprefix -Xlinker ,$(EXTRA_LDFLAGS))

# Common includes and paths for CUDA
INCLUDES  := -I common/inc
LIBRARIES :=

################################################################################

SAMPLE_ENABLED := 1

# Gencode arguments
ifeq ($(OS_ARCH),armv7l)
SMS ?= 20 30 32 35 37 50
else
SMS ?= 11 20 30 35 37 50
endif

ifeq ($(SMS),)
$(info >>> WARNING - no SM architectures have been specified - waiving sample <<<)
SAMPLE_ENABLED := 0
endif

ifeq ($(GENCODE_FLAGS),)
# Generate SASS code for each SM architecture listed in $(SMS)
$(foreach sm,$(SMS),$(eval GENCODE_FLAGS += -gencode arch=compute_$(sm),code=sm_$(sm)))

# Generate PTX code from the highest SM architecture in $(SMS) to guarantee forward-compatibility
HIGHEST_SM := $(lastword $(sort $(SMS)))
ifneq ($(HIGHEST_SM),)
GENCODE_FLAGS += -gencode arch=compute_$(HIGHEST_SM),code=compute_$(HIGHEST_SM)
endif
endif

LIBRARIES += -lcufft

ifeq ($(SAMPLE_ENABLED),0)
EXEC ?= @echo "[@]"
endif

################################################################################

OBJS = main.o kernel.o func.o
CFLAGS = -rdc=true

# Target rules
all: build

build: eseguibile

check.deps:
ifeq ($(SAMPLE_ENABLED),0)
@echo "Sample will be waived due to the above missing dependencies"
else
@echo "Sample is ready - all dependencies have been met"
endif

main.o:main.cu 
    $(EXEC) $(NVCC) $(INCLUDES) $(ALL_CCFLAGS) $(GENCODE_FLAGS) -o $@ -c $<

kernel.o:kernel.cu kernel.h
    $(EXEC) $(NVCC) $(INCLUDES) $(ALL_CCFLAGS) $(GENCODE_FLAGS) -o $@ -c $<

func.o:func.cu func.h
    $(EXEC) $(NVCC) $(INCLUDES) $(ALL_CCFLAGS) $(GENCODE_FLAGS) -o $@ -c $<

eseguibile: $(OBJS) 
    $(EXEC) $(NVCC) $(ALL_LDFLAGS) $(GENCODE_FLAGS) -o $@ $+ $(LIBRARIES)
    $(EXEC) mkdir -p ../../bin/$(OS_ARCH)/$(OSLOWER)/$(TARGET)$(if $(abi),/$(abi))
    $(EXEC) cp $@ ../../bin/$(OS_ARCH)/$(OSLOWER)/$(TARGET)$(if $(abi),/$(abi))

run: build
    $(EXEC) ./eseguibile

clean:
    rm -f eseguibile $(OBJS)  
    rm -rf ../../bin/$(OS_ARCH)/$(OSLOWER)/$(TARGET)$(if $(abi),/$(abi))/eseguibile

clobber: clean

common / inc文件夹是包含Nvidia提供的头文件的文件夹，以使Cuda正确执行;对于标签的关注点，它们在我原始文件中100％正确，但我无法在stackoverflo中复制它们;我得到的错误是：

./kernel.cu(6): Error: External calls are not supported (found non-inlined call to _Z16get_global_indexv)
 make: *** [kernel.o] Error 2

makefile基于Nvidia在样本中提供的文件;我真的不知道错误在哪里;它只是makefile还是我不应该像我刚才那样嵌套函数？

Answer 1

这里有一种情况需要可重定位的设备代码链接（又名separate compilation/linking），但你的Makefile没有正确设置。

有许多情况可能需要单独编译和链接。项目中存在的一个示例是，一个模块中的设备代码调用另一个模块中的__device__函数。在这种情况下，kernel.cu中的AddInts内核正在调用get_global_index __device__函数，该函数在func.cu中定义。这将需要单独编译和链接设备代码。

在这种情况下，解决方案非常简单。我们只需要将相应的-c编译选项更改为-dc，无论它在Makefile中使用它。这3行必须改变：

main.o:main.cu 
    $(EXEC) $(NVCC) $(INCLUDES) $(ALL_CCFLAGS) $(GENCODE_FLAGS) -o $@ -dc $<

kernel.o:kernel.cu kernel.h
    $(EXEC) $(NVCC) $(INCLUDES) $(ALL_CCFLAGS) $(GENCODE_FLAGS) -o $@ -dc $<

func.o:func.cu func.h
    $(EXEC) $(NVCC) $(INCLUDES) $(ALL_CCFLAGS) $(GENCODE_FLAGS) -o $@ -dc $<

                                                                       ^
                                                                       |
                                                        make changes here

此外，您需要根据以下内容更改您的体系结构选择：

SMS ?= 11 20 30 35 37 50

到此：

SMS ?= 20 30 35 37 50

因为sm_11不是用于单独编译和链接的有效体系结构。（如果必须在cc2.0之前的设备上运行此代码，则必须重新构建代码以将所有设备功能包含在同一文件中;您明确表示不希望在您的问题中执行此操作。）

请注意，这不是修改Makefile的唯一方法。你有这样的定义：

CFLAGS = -rdc=true

但你没有在任何地方使用它。代替从-c到-dc进行上述更改，我们只需将$(CFLAGS)添加到这3行中的每一行。结果语法是等效的。（即-dc相当于-rdc=true -c）

不相关的评论是，您发布的代码与cufft库没有依赖关系。因此，您可以更改此行：

LIBRARIES += -lcufft

到此：

LIBRARIES +=

在你的Makefile中

。但是，根据您在此处描述的内容，此更改不是构建正确代码所必需的。如果您的项目最终将使用cufft库，那么您应该按原样保留此行。

无法为CUDA C程序创建工作Makefile

1 个答案: