Re: allow LinuxThreads to have larger stacksfor the mainthread

[Wolfram Gloger <wmglo at dent dot med dot uni-muenchen dot de>]

> > Ok, can someone explain to me that hard limit of 8MB on x86?  I wasn't
> > aware of it at all.  Is this built into LinuxThreads in some other
> > place, or is it a kernel limitation?
> 
> It's a default value in the kernel determined by compile-time constant.
> You can raise the stack size for a process and its chilren.

Ok, so you mean _STK_LIM from include/linux/sched.h?
That is not a hard limit, root can raise it.

> Of course LinuxThreads manages its own stacks for threads which are
> even smaller; this is the normal process stack we are talking about
> that the kernel sets up.

Yep, and I maintain my patch does the right thing: only if the user
has managed to raise her stack rlimit, the bottom of the normal
process stack is set up differently.

> To get thread stacks larger than 2 megs, you can allocate your own
> stacks and set them up at thread creation time via the attribute
> mechanism.

Yes, I know.  Still I find this unecessarily awkward and it makes
every THREAD_SELF call a lot slower if user-defined stacks are used.

Regards,
Wolfram.