Re: Preempt & how long it takes to interrupt (was Re: [2.4.17/18pre]u

[Alan Cox]

> You could make the same argument against SMP, but Linux has SMP support
> despite all the thousands of SMP flaws that once lurked with no obvious
> automated way to find them.  Most of them have been found.

We spent four years on that. It was also done in a very careful and 
precise manner starting with SMP that gave the same guarantees as non SMP
for the 2.0 kernel tree, then moving on to relaxing guarantees in certain
places -as they were audited- for 2.2 and with 2.4 increasing the coverage
to all major points of contention except the scsi layer

> I have a patch to do this for earlier versions of the kernel preemption
> patch - I need to bring it up to date and send it to Robert for use with
> the latest versions of his patch.

Nod - thats a productive approach