Re: [PATCH] limit thread stack size with >4K pages

On Saturday 17 March 2007, Kyle McMartin wrote:
> On Sat, Mar 17, 2007 at 08:47:44AM -0500, James Bottomley wrote:
> > That's a bit ugly ... and would break if someone added new page sizes.
> > Can't we do something like
> > 
> > #if PAGE_BITS > 16
> > #define THREAD_ORDER 0
> > #else
> > #define THREAD_ORDER (16 - PAGE_BITS)
> > #endif
> > 
> 
> Nice.

Nice yes, but doesn't work.
Basically I think it would need to be PAGE_SHIFT  (instead of PAGE_BITS is part of include/linux/raid/bitmap.h).

But with PAGE_SHIFT you get due to missing #includes lots of:
In file included from include/linux/thread_info.h:21,
                 from include/linux/preempt.h:9,
                 from include/linux/spinlock.h:49,
                 from include/linux/module.h:9,
                 from init/main.c:13:
include/asm/thread_info.h:37:5: warning: "PAGE_SHIFT" is not defined

Adding more #includes isn't a good idea either.

I still propose my initial patch: http://lists.parisc-linux.org/pipermail/parisc-linux/2007-March/031423.html
If someone adds new page sizes (is this likely?), he will stumble over the not-defined THREAD_ORDER anyway and will have to fix it acordingly.

Helge