MAXD Size

[Brian J Newton]

I made a change to a box to set the maxd parameter to allow for max process size of 2gig. This did not allow processes (after reboot) to exceed 1 gig even though the system had plenty of memory.

Is 1 gig the real limit even though the documentation says 2 gig?

[T G Manikandan · Accepted solution]

The address space is divided into quadrants.
The process has a limitation of not exceeding 960MB maxdsiz.

If your exe is enabled with EXEC_MAGIC options it could exceed that limitation.

For a detailed explanation you can check /usr/share/doc/proc_mgt.txt

[Bill Hassell]

maxdsiz can be set to a very large value (more than 3Gb if necessary) but your 32 bit program is severely constrained by 32 bit pointers and the method by which the four program quadrants are handled. The default a normally-compiled program is about 960 megs. Recompile your program with -W1 -N to raise the address limit to about 1750 megs. With recent patches, you can use the +q3p option and go above 1750 megs. NOTE: read the two white papers about 32bit programs and data space limits found in /usr/share/doc called mem_mgt and prog_mgt. If you only have 11.11 opsystems, you'll need to read the papers online at docs.hp.com as there are numerous considerations about making 32bit programs address large areas of memory.

By the way: all of these limitations are eliminated if you compile the program as a 64bit program.

[Bill Hassell]

Sorry about the typo: proc_mgmt is the filename. I have attached a short program that compiled as a 32bit program will show the limitations.