> Benchmark utilities to measure the overhead of syscalls. It's cheating > to do for getpid, but for other things like gettimeofday, it's > *extremely* nice. Linux's gettimeofday(2) beats the socks off of the > rest of the time implementations. About the only faster thing is to > get CPU speed and use rdtsc. Certainly no other OS allows you to get > the timestamp faster with a syscall.
Here is where my memory gets hazy, however Solaris 2 had a very fast implementation of gettimeofday(), it was still a syscall I think but had a shortcut in the kernel. This was added (If I rembember correctly) to get a database (Sybase I think) to run on Solaris 2 as fast as it always used to run on SunOS. This was commented in the code as a special, ugly hack as a result of extreme pressure from an important customer. I wonder if Linux inherited the hack from Solaris? -Steve
