I've got an auxiliary function that does some operations that are pretty costly.
I'm trying to profile the main section of the algorithm, but this auxiliary function gets called a lot within. Consequently, the measured time takes into account the auxillary function's time.
To solve this, I decided to set and restore the time so that the auxillary function appears to be instantaneous. I defined the following macros:
#define TIME_SAVE struct timeval _time_tv; gettimeofday(&_time_tv,NULL);
#define TIME_RESTORE settimeofday(&_time_tv,NULL);
. . . and used them as the first and last lines of the auxiliary function. For some reason, though, the auxiliary function's overhead is still included!
So, I know this is kind of a messy solution, and so I have since moved on, but I'm still curious as to why this idea didn't work.
Can someone please explain why? Ubuntu 10.04 x86_64.