If you have a 2.4.x kernel and want the likeness real-time speed of a 2.6.x kernel you need some patches..
  • *kernel-patch-2.4-lowlatency
    *kernel-patch-2.4-preemp
This patches on the 2.4.x kernels are already integrated on the 2.6.x kernels
During the 2.4 Linux kernel series, Robert Love of Novell/Ximian fame released a well-known kernel patch that enabled higher preemption and that could be applied to the standard Linux kernel source. Other patches, such as a low-latency patch from Ingo Molnar, a core Linux kernel contributor since 1995, further extended the capabilities of this patch by reducing latency throughout the kernel. A key concept for the TimeSys products and these patches was to replace spin-locks with mutexes (mutual exclusion mechanisms) whenever possible. These provide the resource security and integrity required by the kernel without causing the kernel to block and wait. The core concepts pioneered by these patches now are integral parts of the 2.6 Linux kernel.
Info from Real-Time and Performance Improvements in the 2.6 Linux Kernel

You need
  • *kernel 2.4.x source code
    *The two patches above
    *experience on kernel compile
To active the options on the make x-config or make menuconfig, search the label "Procesor type and Features", mark low latency and preemp options...compile(at your own risk) and all set.

ATTENTION: this is not a performance BOOST! It only generates a more responsible kernel for the 2.4.x series kernel...