memory limitations per process

[af300wsm at gmail.com]

On Feb 19, 2009 4:21pm, Ivan Voras <ivoras at freebsd.org> wrote:


> Your question is vague.


Sorry, it was not intentional. I wasn't too sure how to ask the question.



> A 32-bit process can only access 4 GB of memory, but all processes also

> have a bit of memory "reserved" for the kernel. On FreeBSD the

> accessible memory for processes is closer to 3 GB than 2 or 4. See this

> discussion for details: http://wiki.freebsd.org/KVA_PAGES



> Also, FreeBSD processes have administrative limits to their size set by

> defaults. See for example this:

> http://unix.derkeiler.com/Mailing-Lists/FreeBSD/questions/2008-11/msg01363.html

> . If you want to use the whole 3 GB for a process, you'll have to

> increase maxdsiz. Note that you may need to experiment with this size

> since your BIOS will probably not let you use 4 GB of physical memory

> for the OS except if you enable PAE, and it's possible to create an

> unbootable system by messing with kernel memory limits. You should

> probably experiment on the loader command line first, not in the

> loader.conf file.




Thank you. This is exactly what I was hoping to learn. Thanks also for the  
links for further reading.

Andy