[Linux-ia64] Re: [PATCH] Increase size of user stack

[Martin Hicks <mort@wildopensource.com>]

On Mon, May 05, 2003 at 11:25:33AM -0700, David Mosberger wrote:
> >>>>> On Mon, 5 May 2003 14:18:52 -0400, Martin Hicks <mort@wildopensource.com> said:
> 
>   Martin> The current user stack size limit of 2GB is not big enough
>   Martin> for large SMP or SSI clusters.  The following patch
>   Martin> increases this size from 2GB to 512GB.  The new size is
>   Martin> negotiable, but right now SGI has programs that require over
>   Martin> 100GB of stack size on a 64 processor machine.  Setting the
>   Martin> user stack size to 512GB seems like a reasonable thing to do
>   Martin> for future growth.
> 
> Why not make it configurable via setrlimit() and be done with it once
> and for all?

(sorry for taking so long to respond about this)

The user stack size is configurable through setrlimit().  The default 
size of the user stack is 8MB and the max is ~0UL.  The problem is
the addreses that are chosen for the stack (which grows down) and the
register backing store (which grows up) are only 2GB apart.  My patch
simply makes this space 512GB so that large stack are possible, without
the stack smashing into the RBS.

mh

-- 
Wild Open Source Inc.                  mort@wildopensource.com