Re: 2.4.4 sluggish under fork load

[Linus Torvalds]

On Sat, 28 Apr 2001, Peter Osterlund wrote:
> 
> For example, when running the gcc configure script, the X mouse pointer is
> very jerky. The configure script itself runs approximately as fast as in
> 2.4.3.

Ok. Fair enough. The new "run the child first" approach has advantages,
but it is entirely possible that the advantages unfairly prioritize things
that do a lot of forking.

> Another thing is that the bash loop "while true ; do /bin/true ; done" is
> not possible to interrupt with ctrl-c.

This, however, is a bash bug, not a kernel issue. Bash does something
strange with the terminal and ignores ^C at times, and basically only
react correctly to the ^C under the right circumstances. Changing the
child to run first probably makes the pre-existing bug much easier to see.

> Reverting the fork patch makes all these problems go away on my machine.

Reverting it outright may be an acceptable approach. I'll think about
it: the arguments _for_ the patch are true and real, and it shows up as
real improvements on some things..

An alternative approach might be to not give the child the _whole_
timeslice, but give it more than half. Partition it out 66% - 33% or
something.

		Linus