I have just committed some changes that make /bin/sh vfork(2) when it can.
For something like:

for i in $(jot 2000); do /bin/echo -n; done

This results in a 30-50% speed improvement.

If you discover any problems that this caused, please feel free to email
me and send-pr.  ;-)

 == Roland Dowdeswell                      http://www.Imrryr.ORG/~elric/  ==
 == The Unofficial NetBSD Web Pages        http://www.Imrryr.ORG/NetBSD/  ==
 == The NetBSD Project                            http://www.NetBSD.ORG/  ==