2.4.4+fork patch still sluggish

[Jeffrey Kuskin <jsk@atheros.com>]

This is basically a followup to the "2.4.4 sluggish under fork load"
thread.

I am using Redhat 7.1 on a 128MB 400 MHz PII system.  I have a
locally-built 2.4.4 kernel to which I manually applied the patch that backs
out the child-before-parent behavior on a fork.  Namely, this patch:

  <http://boudicca.tux.org/hypermail/linux-kernel/2001week17/1288.html>

However, even with this patch applied, I still see extremley jerky mouse
pointer behavior when I run any kind of job that does lots of forking.  For
example, a kernel compile or even just the "configure" in preparation for
compiling XEmacs.

The same behavior, on exactly the same machine, did _not_ occur with Redhat
6.2/kernel 2.2.19.

I see that this patch has recently been merged into 2.4.5-pre1, but I am
concerned that it does actually fix the underlying problem.

Do others continue to see "jerky mouse pointer" behavior even with this
patch installed, or should I look for other causes?  For instance, are
there known problems with jerky mouse pointer behavior under heavy swapping
load?

-- 
Jeffrey Kuskin                              Tel: +1-408-773-5256
Senior System Engineer                      Fax: +1-408-773-9940
Atheros Communications                      http://www.atheros.com
jsk@atheros.com