a hot swap kernel would be something like the holy grail of kernel
hacking. it would logically go something like this:

void kexec_hot_swap()
{
        void *kern = load_kernel_into_mem();
        syscall_queue(ENABLE); /* queue all sys calls */
        irq_queue(ENABLE); /* queue all irqs */
        /* bring new kernel's state inline with current one's.
           this includes all data structures, module hooks, etc.
           this needs to be very fast as irqs will be pending... */
        synch_kernel(kern);
        kernel_start(kern); /* fire in the hole... */
}

at this point the new kernel would know it is being started as a
hot swap throught a flag or something, and dequeue the irq's
that are pending, followed by the sys calls that are waiting.
if this goes how i think it should, a user running on the system
wont even know the kernel was swapped.

what do you think? is it do-able?

=====
Main Entry: anom·a·lous 
1 : inconsistent with or deviating from what is usual, normal, or expected: IRREGULAR, UNUSUAL
2 (a) : of uncertain nature or classification (b) : marked by incongruity or contradiction : PARADOXICAL
synonym see IRREGULAR

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