Re: [RFD] Combined fork-exec syscall.

[Mark Grosberg <mark@nolab.conman.org>]

On Sun, 27 Apr 2003, Werner Almesberger wrote:

> How about
>
>     fdrplc(3,fmap);
>     exec("/bin/cat",...);

Not a bad idea. Although my initial motives were to try and reduce the
number of syscalls for forking processes, I can see this as kind of a
useful call as well.

> 0) System call names must be short and cryptic :-)

Heh. How about something like fdmap_set()?

> 1) Requiring the kernel to iterate over the array element by element
>    in order to find out how big it is may be inefficient. Better to
>    pass the length.

Good point. Just a quick verify_area() check and then process away.

> 2) System call overhead is marginal, particularly in this case.

Depends. I know that on the one multi-user Linux machine I do use on a
day-to-day basis syscall overhead is painful:

  Calibrating delay loop.. ok - 16.59 BogoMIPS

and considering this is a multi-user machine with quite a few users always
tapping away doing quick commands (edit this file, run this program, copy
this file, ...).

> 3) There may be other uses than exec(2), where a way for closeing
>    all fds and getting a new set may be useful.

Agreed.

L8r,
Mark G.