Re: x86 question: Can a process have > 3GB memory?

[Andrea Arcangeli]

On Tue, May 07, 2002 at 04:08:55PM -0700, Robert Love wrote:
> On Tue, 2002-05-07 at 16:03, Clifford White wrote:
> 
> > We are working with a database that requires a large amount of memory
> > allocated by a single process.
> > This is on an Intel 32-bit platform.
> > We'd like to go > 3GB of memory per process.
> > Is this possible on a 32-bit machine? I have been reading the various
> > 'highmem' discussions, but that's kernel page tables...
> > Or is this a glibc issue, and not proper for a kernel-list question?
> > Any pointers would be appreciated. The Intel ESMA (Extended Server Memory
> > Arch) page states that it's possible, but.....how?
> 
> You can go to 3.5GB, anything more and stuff starts getting real tight
> and not very nice.  You can only do 3.5/0.5 on non-PAE, though - PAE
> requires segments to be aligned on 1GB-boundaries.
> 
> The attached patch (for which credit goes elsewhere - Ingo or Randy, I
> think?) implements the full range of 1 to 3.5GB user space partitioning,

actually I'm the one who wrote the 3.5G config option both in 2.2 and
recently I forward ported it to 2.4 due the number of requests I was
getting.

> selectable at compile-time.
> 
> 	Robert Love
> 

Andrea