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

From: Dave Chinner
Date: Thu May 29 2014 - 20:21:21 EST


On Thu, May 29, 2014 at 08:06:49PM -0400, Dave Jones wrote:
> 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

Right, but it doesn't throw loud warnings when a specific threshold
is reached - it just issues a quiet message when a process exits
telling you what the maximum was without giving us a stack to chew
on....

Cheers,

Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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