Help Measuring Fork/Exec Overhead

[Niket K. Patwardhan]

>From: juhlin at druak.UUCP (JuhlinB)
>Subject: Help Measuring Fork/Exec Overhead
>Date: 20 Aug 85 23:33:29 GMT
>To:       info-unix at brl-tgr.arpa

I did some of this at INTEL. We decided to include 1 exit() , 1 wait() and 2
task switches as part of the fork overhead. Reason: if you do a fork() you
cannot escape the fact that these events are eventually going to happen - at
some time! On our systems there was almost always enough memory that it was not
necessary to swap out the child to do the fork, so the results were consistent.

The task switches were important:- on the implementation we had, it could take
upto 5mS to do the task switch! (And you cant escape that order of magnitude
with any of the usual C compilers for the 286 for UNIX style switching!)