I have to perform performance benchmark on a slow CPU with scarce memory resource. Doing a printf as shown below slow down the performance severely (There is another 'action start/end' benchmark in main()). For eg. from 40ms -> 4000ms :O. Is there any more efficient way to get time for benchmark result??

void func(){
struct timeval sTime;
gettimeofday(&sTime, NULL);
printf("SOAP sec start: \t %ld\n", sTime.tv_sec);
printf("SOAP usec start: \t %ld\n", sTime.tv_usec);

// SOAP parsing operation

printf("SOAP sec end: \t %ld\n", sTime.tv_sec);
printf("SOAP usec end: \t %ld\n", sTime.tv_usec);
}

Well maybe you could get the start time store it in a variable, get the finish time, store it in a variable then do all the printing after the operations you wish to time. There will still be a little inaccuracy in the call to gettimeofday(), but that's just the effect that observing a phenomenon will affect the phenomenon being observed.