Lennart Sorensen wrote:

How would you deal with something like a pentium 4 HT processor where
you may run slower just because you got scheduled on the sibling of a
cpu that happens to run something else needing the same execution units
you do, causing you to get delayed more, even though the cpu is running
full speed and nothing else is trying to use your "cpu"?  I don't think
there is any way to know what the real impact of two processes on a HT
cpu have on each other.

Interesting goal.  Not sure it can be done.

You're right.  That's a very tough case.  I don't know if there's any
way to do a reasonable estimate of the slowdown.  You could handwave it
and say "if both threads are running a process, then apply an X scaling
factor to their rate of progress".  That might be enough.

    J