The results will *always* be wrong as you can't observe a process without skewing it. (As established by Heisenberg...) The point is that cachegrind can measure things that other methods can't, but it's not good for everything.
/ Fredrik (Naranek) Hubinette (Real Build Master)
Previous text:
2004-01-17 14:30: Subject: file limits
You'll also get (larger) problems with threaded programs. The results will be wrong regardless of whether you use real or emulated time for scheduling. If you use the real time, preemption will occur too often. If you use emulated time, threads doing system calls will appear to reenter the ready state too soon or too late, depeding on how much emulated time you account for the system call (it's not practical to try to compute the amount correctly).
/ Marcus Comstedt (ACROSS) (Hail Ilpalazzo!)