gpu_activity.c

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/*
 * Author: Sangamesh Ragate
 * Date : 18th Nov 2015
 * ICL-UTK
 * Description : This is the parent process that Preloads the libactivity.so
 * and launches the cuda application for performing PC-Sampling
 */


#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <sys/wait.h>

#include "path.h"




int main(int argc,char** argv){


    int pid;
    if(argc < 2){
        printf("please supply Cuda app to be profiled \n");
        exit(-1);
    }


    //get CUDA device ID and sampling rate from args
    char *samp, *device;
    extern char* optarg;
    extern int optind;
    int c,tmp,index;
    
    //set default samp and device
    device="0";
    samp="5";
    index=1;
    while((c=getopt(argc,argv,"d:s:"))!=-1){
        switch(c){
            case 'd':
                device = optarg;
                tmp=atoi(device);
                index = optind;
                if(tmp < 0){
                    printf("GPU device ID not valid \n");
                    exit(-1);
                }
                break;
            case 's':
                samp = optarg;
                tmp=atoi(samp);
                //record index for argument forming for cuda app
                index = optind;
                if(tmp < 0 || tmp > 5){
                    printf("PC sampling rate not valid \n");
                    exit(-1);
                }
                break;
            case '?':
                printf("Switch not recognized by papi_sampling_cuda utility \n");
                break;
        }
    }

    
    //form the arg list for the cuda app
    char** var;
    var=&argv[index];
    

    char* ld_lib;
    char env1[1024];
    char env2[256];
    char env3[256];
    int status;

    //get the shared library load path
    strcpy(env1,"LD_LIBRARY_PATH=");
    ld_lib=getenv("LD_LIBRARY_PATH");
    if(ld_lib == NULL){
        printf("Error loading CUDA shared libraries: LD_LIBRARY_PATH=NULL \n");
        exit(-1);
    }
    strcat(env1,ld_lib);

    strcpy(env2,"GPU_DEVICE_ID=");
    strcat(env2,device);
    
    strcpy(env3,"PC_SAMPLING_RATE=");
    strcat(env3,samp);

    //form the env variable
    char* env[]={env1,env2,env3,ld_prld, NULL};

    printf("\n\n\n\n");
    printf("***************** PAPI_SAMPLING_CUDA utility **********************\n");
    pid=fork();
    if(pid==0){
        execve(var[0],var,env);
    }else if(pid==-1){
        printf("Profile fork failed \n");
        exit(-1);
    }else{
        wait(&status);
    }
    return 0;
}