Hi Joel...
Manish is right. Please notice that he talked about "why do we do copy
on write (COW) if soon after child is forked, it quickly does exec()".
So yes, COW has overhead, but imagine if parent ran first. COW will be
triggered for parent address space, then child soon runs too. Then it
issues exec(). Clearly, this waste certain amout of memory which can
be fairly avoided if child runs first
It is more about waste of work, than waste of memory. Memoy will anyway be reclaimed/reused when we do exec()
Thanks,
-nagp
