Re: [13/18] x86_64: Allow fallback for the stack

Christoph Lameter
2007-10-04T21:20:30Z

On Thu, 4 Oct 2007, Rik van Riel wrote:

> > Well we can now address the rarity. That is the whole point of the
> > patchset.
>
> Introducing complexity to fight a very rare problem with a good
> fallback (refusing to fork more tasks, as well as lumpy reclaim)
> somehow does not seem like a good tradeoff.

The problem can become non-rare on special low memory machines doing wild
swapping things though.

> > It will be more common if the stack size is increased beyond 8k.
>
> Why would we want to do such a thing?

Because NUMA requires more stack space. In particular support for very
large cpu configurations of 16k may require 2k cpumasks on the stack.

> 8kB stacks are large enough...

For many things yes. I just want to have the compile time option to
increase it.