Re: [coreboot] Question about STACK_SIZE

[Patrick Georgi]

Am 02.05.2013 16:32, schrieb Aaron Durbin:
> I am wondering why the ramstage stack size is so large on a lot of boards:
> Is this just an artifact of copy-n-paste? What is driving the
> requirement for such large stack sizes?

Other than for wakeup-from-suspend, no-one ever cares if that's 4k or
400k, except that things might fail if it is too small.

And Google is the first organisation with a huge interest in an
optimized wakeup in coreboot.

Patrick

Question about STACK_SIZE

[Aaron Durbin]

On Thu, May 2, 2013 at 10:40 AM, Patrick Georgi  wrote:
> Am 02.05.2013 16:32, schrieb Aaron Durbin:
> > I am wondering why the ramstage stack size is so large on a lot of boards:
> > Is this just an artifact of copy-n-paste? What is driving the
> > requirement for such large stack sizes?
>
> Other than for wakeup-from-suspend, no-one ever cares if that's 4k or
> 400k, except that things might fail if it is too small.

Presumably the stack poisoning has somewhat of an impact on boot times
and coreboot users generally care about that? 64KiB stack with
MAX_CPUS = 16 is 1MiB of memory just for stack and it's poisoning.
It's definitely not dire, but just something to think about. I'm not
sure what the expectations are for boot time from existing users.

-Aaron

Question about STACK_SIZE

[Stefan Reinauer]

* Patrick Georgi  [130502 17:40]:
> Am 02.05.2013 16:32, schrieb Aaron Durbin:
> > I am wondering why the ramstage stack size is so large on a lot of boards:
> > Is this just an artifact of copy-n-paste? What is driving the
> > requirement for such large stack sizes?
>
> Other than for wakeup-from-suspend, no-one ever cares if that's 4k or
> 400k, except that things might fail if it is too small.
>
> And Google is the first organisation with a huge interest in an
> optimized wakeup in coreboot.
>
> Patrick

It is true. As soon as coreboot has suspend/resume enabled, the memory
used by coreboot is permanently lost to the OS. While nobody cares about
400K missing on a 4G system, it would still be nice to only use what we
need; Otherwise people could start thinking coreboot is a big and clunky
firmware framework rather than a sleek and slim solution.

Stefan