Where did you get all this from? Is it documented somewhere, or is it something
you've 'soaked up through your fingertips' over the years?
So I went back to the FMs. For any question of kind "How does that UNIX
service behave regarding MVS resources, attributes, etc.", I always read
what the "z/OS UNIX System Services Programming - Assembler Callable
Services Reference" tells me. If something is to be said, there is a
section called "Usage Notes". Here are some interesting snippet:
For fork() it says:
- The child process inherits the MEMLIMIT of the parent.
- The child address space inherits the following address space
attributes of the parent address space: region size and time limit.
For spawn() it says:
- The region size of the parent is inherited by the child, unless the
INHESETREGIONSZ flag in the inheritance structure is set on to indicate
that the value specified in INHEREGIONSZ is to be used to determine the
child's region size. For more information, see What are soft limits? in
z/OS UNIX System Services Planning and Inheriting soft limits in z/OS
UNIX System Services Planning.
- The MEMLIMIT of the parent is inherited by the child, unless the
INHESETMEMLIMIT flag in the inheritance structure is set on to indicate
that the value specified in INHEMEMLIMIT is to be used to determine the
child's MEMLIMIT.
Another useful source of information is "z/OS UNIX System Services
Planning". This FM says about MAXASSIZE:
MAXASSIZE is the maximum region size (in bytes) for an address space
that was created by rlogind, telnetd, and other daemons. The MAXASSIZE
value limits the combined size of above and below the 16 M line storage.
If MAXASSIZE is greater than LDALIMIT (the <16M limit), then the LDAELIM
(the >16M limit) is set to MAXASSIZE - LDALIM.
You can set a system-wide limit in BPXPRMxx and then set higher limits
for individual processes. Use the RACF ADDUSER or ALTUSER command to
specify the ASSIZEMAX limit on a per-process basis as follows:
ALTUSER userid OMVS(ASSIZEMAX(nnnn)
This manual also has a couple of pages discussing all about limits. Of
special interest to this discussion it the section called "How are
limits handled after an identity change?", and the following sections.
Its too much to copy&paste here. I suggets you have a read if your
interested. (I've got the impression this part has not always be there
in that detail. Great it is now)
--
Peter Hunkeler
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
