RE: [problem] RH 2.4.7-2 kernel slows to a crawl under heavy i/o

["Jeff Busch" <jbusch@half.com>]

> I have been trying to duplicate a similar problem in my lab that happened
> to me on a production box with 2.4.5. do you have a test that will allow
> you to replicate the problem at will?

ok here's a reply from our developer:

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probably the best way to reproduce the environment would be to write a
C++ class that has a method on it that goes and maps a file, touches
all the memory in that file, and then returns.  add another method
that takes a number and returns that same number.  then run that code
through swig and write a mod_perl interface to call the first method
then call the second method in a loop (10 times should be good), then
storable::freeze an array of results and print it to stdout.

this ought to emulate the kinds of things we do there.  you might
actually have that method take a number and return a string (literal)
instead of a number, just to exercise swig a little more.

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Note that the file must be large; maybe 50% greater than physical RAM.

Jeff