[clug] Linux max memory per process

Arafangion thestar at fussycoder.id.au
Thu Nov 17 02:48:23 GMT 2005

On Thu, 17 Nov 2005 02:20 pm, Pearl Louis wrote:
> Hi guys
> Just a quick question.  What is the maximum memory per process that
> you can have in Linux, both on 32-bit machines and 64-bit machines and
> for both 2.4 and 2.6 kernels?  Also, this limit includes both physical
> RAM and virtual memory right?

This is just my impression after learning C, but here goes, if I'm wrong, 
correct me.

Generally, there is a unique pointer for every char that the process can 

Thus, when using 32-bits, there is a limit of (2^32)*CHARBITS

CHARBITS is usually 8, but could be larger.

This apparently turns out to be about 4 GB. For 64-bit machines, I'd expect 
that you'd be able to address an unbelievable amount of memory.

If 4 GB isn't enough, there are usually tricks (One I can think of at the 
moment is to use paging).

> Thanks very much!
> Pearl

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