On 10/13/2011 9:12, andrel wrote:
> Might be, but why design it this way? Why has cntrl-alt-del not a higher
> priority than disk-IO and indeed any other program/process?

Sure, but what's it going to do when it gets that keystroke? It has to fire 
up the code that handles it, presents the UI, etc.  *That* is what takes 
time to page in.

> modern machines: why not dedicate one core to the OS and the OS alone?)

The core isn't the problem. The disk is the problem, because rescheduling 
disk is slow. You can interrupt the CPU in a few hundred machine cycles. You 
can't really interrupt a disk seek.

Indeed, I suspect if Windows figured out your startup programs, figured out 
that you actually have more than enough RAM to load them all, and would just 
load the entire file sequentially instead of letting them page in on demand, 
you'd cut boot time tremendously.

> IIRC also the Amiga did not suffer from virtual lock up (nor do I remember
> it so badly from earlier version of MS-DOS).

The Amiga didn't have demand paging, so you only suffered a long shut-down 
time when you had allocated a lot of small chunks of memory and needed to 
deallocate them before exiting. That happened on occasion.

-- 
Darren New, San Diego CA, USA (PST)
   How come I never get only one kudo?

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