Re: Performance issue on dual Athlon MP

[Alan Cox]

> BTW, this doesn't seem like a preemption issue, considering that throughput
> is very definitely affected as well as latency.
> 
> Anyway, please let me know if there's anything I can do, within my
> constraints, to help.  (As you can guess, though, I don't have any kernel
> debugging experience.)

It sounds like the hit you are taking is from highmem and I/O (having to
copy pages lower into memory so the I/O subsystem can use them). Some of
that is in the hard to fix for 2.4 category with the x86. There are some
experimental patches around but they are experimental.