Re: 2.4.17 absurd number of context switches

[Alan Cox]

>         local_irq_disable();
>         if (current->counter > 0)
>             --current->counter;
>         local_irq_enable();

Umm: SuS sayeth..

   DESCRIPTION

     The sched_yield() function forces the running thread to relinquish the
     processor until it again becomes the head of its thread list. It takes
     no arguments.

Which doesnt seem to be what you are doing.