Re: [RFC 2/2] x86_64: expand kernel stack to 16K

Dave Jones
2014-05-30T00:07:22Z

On Fri, May 30, 2014 at 09:53:08AM +1000, Dave Chinner wrote:

> That sounds like a plan. Perhaps it would be useful to add a
> WARN_ON_ONCE(stack_usage > 8k) (or some other arbitrary depth beyond
> 8k) so that we get some indication that we're hitting a deep stack
> but the system otherwise keeps functioning. That gives us some
> motivation to keep stack usage down but isn't a fatal problem like
> it is now....

We have check_stack_usage() and DEBUG_STACK_USAGE for this.
Though it needs some tweaking if we move to 16K

I gave it a try yesterday, and noticed a spew of noisy warnings as soon
as I gave it a workload to chew on. (Moreso than usual with 8K stacks)

Dave