Re: pmap

[Matt Thomas <matt%3am-software.com@localhost>]

On Mar 26, 2008, at 6:10 AM, raymond.meyer%rambler.ru@localhost wrote:

> Below is the output of pmap. The question is - how come it shows 3  
> stack
> regions? I thought a running application had only 1 stack??
>
> [root@ultra10] pmap -s
> FF7FE000   6144K                     [ stack ]
> FFDFE000   1928K read/write          [ stack ]
> FFFE0000    120K read/write          [ stack ]

It's all one stack, just divided into three segments.
if you total them up you get 8192K which is the hard stack limit.
the default stack size is 2048K of which you've used 120K
worth.

The system always reserves enough space for the hard stack limit.
It maps the default stack limit as anon pages.  As the system
advances down the stack by getting page faults, uvm_grow is called
to record the depth of the stack.