Re; 4KSTACKS again. Thanks...

[Tom Mitchell]

Thanks,
On Sat, Apr 17, 2004 at 06:23:02PM -0400, Alan Cox wrote:
> On Sat, Apr 17, 2004 at 01:33:40PM -0700, Tom Mitchell wrote:
> > I am curious why the change to 4K stacks was made.
> > I assume from comments that it permits mapping an invalid page 
> > to trap overflow errors.
> 
> You have a kernel stack per process. Thats a lot of memory. This stack is
> used for syscall processing and also interrupts ocuring when that thread
> runs. You may also get nested interrupts so the stack needs to be big
> enough for a probable worst case, which means 4K or so alwayd free for
> interrupts.
> 
> If you have 4K per process and seperate stacks per IRQ its more efficient
> and more reliable.

Thank you.

-- 
	T o m  M i t c h e l l 
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