Re: stack size

[lsorense@csclub.uwaterloo.ca (Lennart Sorensen)]

On Tue, Apr 22, 2008 at 11:57:35PM -0700, Francesco Pietra wrote:
> 
> On increasing the size of the molecule treated, the procedure immediately crashed with error message
> 
> what (): St9bad_alloc
> 
> Failure of the () operator was attributed by the program developers to memory exhausion (UMA system, 4 dual-opteron 875, ecc 24GB, of which 1 for debian amd64 etch, set with shmmax). On request I showed 
> 
> ulimit -a
> 
> core file size          (blocks, -c) 0
> data seg size           (kbytes, -d) unlimited
> max nice                        (-e) 0
> file size               (blocks, -f) unlimited
> pending signals                 (-i) unlimited
> max locked memory       (kbytes, -l) unlimited
> max memory size         (kbytes, -m) unlimited
> open files                      (-n) 1024
> pipe size            (512 bytes, -p) 8
> POSIX message queues     (bytes, -q) unlimited
> max rt priority                 (-r) 0
> stack size              (kbytes, -s) 8192
> cpu time               (seconds, -t) unlimited
> max user processes              (-u) unlimited
> virtual memory          (kbytes, -v) unlimited
> file locks                      (-x) unlimited
> 
> The comment was: The item that is suspiciously small is the stack size. Did you try to set it to unlimited?
> 
> I did, with 
> 
> ulimit -s unlimited
> 
> though, () failure was not solved. I am still investigating the issue.
> 
> >From that, I extrapolated (now clearly wrongly) that setting stack size to unlimited may be beneficial to have all available memory used in memory-demanding computation.

Well the stack is only used for passing arguments to functions and for
local variables in a function.  Most large chunks of data are allocated
using malloc which means it comes from the heap, not the stack.

It takes a rather badly designed program to use 8MB of stack space.

-- 
Len Sorensen