I need to increase the FD_SETSIZE value from 1024 to 4096. I know it'd be better to use poll()/epoll() but I want to understand what are pros/cons. The main question is: have I to recompile glibc? I read several thread where the change of .h after changing FD_SETSIZE works recompiling only the user application. Reading the glibc code (and the kernel too), actually it seems to me that if I want to use select(), FD_* macro and so on, I have to recompile all because the size of fd_set is changed. At this point I have to recompile all not only my application because if in the system there is an another "common" application that uses select and friends, I could have problem. Am I right?