sampath@mars.njit.edu (sampath s k) (02/03/91)
Hi,
Program:
--------
I have a program that builds a huge graph. During the
graph building phase a lot heap space (malloc()) is
used and a lot of stack space is used during the graph
traversal as it is extremely recursive.
Environment:
--------
The above mentioned program is tested on an IBM RS6000
(model 530 AIX 3.1) with ~ 80 MB of real memory and 256 MB
of paging space.
Problem:
--------
The program is abnormally terminated during the graph traversal
phase for lack of paging space. Increasing the paging space beyond
256 MB doesn't seem to help.
Question:
---------
Is it possible possible for the above mentioned program to work
if I thrown in extra memory boards? Do extra memory boards
increase the data (heap+stack) space? Please shed some
light on this issue. Thanks for your time.
-- sampath sampath@mars.njit.edu frank@leopard.austin.ibm.com (02/06/91)
> The program is abnormally terminated during the graph traversal > phase for lack of paging space. Increasing the paging space beyond > 256 MB doesn't seem to help. Are you sure that it is being terminated for 'paging space' and not because you are out of heap? I forget what the default heap is, but look into the ulimit command (for ksh or sh). To increase your limit, have the administrator use smit to change your user options. > --------- > Is it possible possible for the above mentioned program to work > if I thrown in extra memory boards? Do extra memory boards > increase the data (heap+stack) space? Please shed some > light on this issue. Thanks for your time. No, extra real memory does not effect your data, heap or stack space. Also, there is a hard limit of 256 MB per segment. This means that unless you do some programming tricks (which I don't know the specifics of) you are stuck at this limit. - Frank Feuerbacher Disclaimer: I don't speak for my employer and they don't speak for me.
jfh@rpp386.cactus.org (John F Haugh II) (02/09/91)
[ Frank mistakenly redirected this to comp.unix.wizards. Since it only applies to AIX v3 I am sending it back to comp.unix.aix ] In article <5141@awdprime.UUCP> ...@cs.utexas.edu:ibmaus!auschs!leopard.austin.ibm.com!frank writes: >> The program is abnormally terminated during the graph traversal >> phase for lack of paging space. Increasing the paging space beyond >> 256 MB doesn't seem to help. > >Are you sure that it is being terminated for 'paging space' and not because >you are out of heap? I forget what the default heap is, but look into the >ulimit command (for ksh or sh). To increase your limit, have the administrator >use smit to change your user options. Better still, vi the file /etc/security/users and look at the values in the "default" stanza. Change them there so that everyone can benefit. But be careful that you don't change to too big or no one may be able to log in any longer ... >No, extra real memory does not effect your data, heap or stack space. Also, >there is a hard limit of 256 MB per segment. This means that unless you do >some programming tricks (which I don't know the specifics of) you are stuck >at this limit. Memory map a file or create a shared data segment. Either of these two techniques will create room for an additional 256MB of address space. Regrettably malloc() doesn't know about this trick (nor should it, if you consider the behavior of mapped files and shared segments with respect to fork and exec and how your data segment behaves with respect to both of those system calls ...). -- John F. Haugh II UUCP: ...!cs.utexas.edu!rpp386!jfh Ma Bell: (512) 832-8832 Domain: jfh@rpp386.cactus.org "I've never written a device driver, but I have written a device driver manual" -- Robert Hartman, IDE Corp.