On Friday 24 March 2006 18:24, s45_nospam@free.fr stood up and spoke the
following words to the masses in /comp.os.linux.misc...:/

> My kernel is a 2.4.21-20.0.1.ELsmp, not a 2.4.21-20.0.1.ELhugemem.
> Refering to
>
http://www.redhat.com/docs/manuals/e...ch-kernel.html,
> does it mean that the kernel 2.4.21-20.0.1.ELsmp works with 8GB of
> RAM but is not optimized at all?

Negative... In order to make use of more than 4 GB worth of physical
memory on an IA32 machine (or an IA32-64 running a 32-bit operating
system), you need to have an /i686/ or better CPU - i.e. Pentium Pro
and above or equivalent - and you need a kernel that has been compiled
with support for up to 64 GB, which will be addressed in a paged mode
via three-level paging.

> I understand that kernel-hugemem is required for memory configurations
> higher than 16 GB, and 2.4.21-20.0.1.ELsmp is enough with 8 Gb.

Negative again. The /kernel-hugemem/ is required for memory
configurations above 4 GB.

There are only three memory capacity configurations in the Linux kernel:
- no /HIGHMEM/ support : supports up to 1 GB
- /HIGHMEM/ support : supports up to 4 GB
- /HIGHMEM_64/ support : supports up to 64 GB by running the CPU in PAE
(Physical Address Extension) mode.

The latter is why you need an /i686/ or better. /i586/ does not have a
PAE mode.

> I need the smp kernel because I have got 2 Intel Xeon.

Normally, the /kernel-hugemem/ will also support SMP. There's very
little point in having it configured as a uniprocessor kernel, as
32-bit machines with more than 4 GB of physical memory installed are
typically SMP machines. ;-)

--
With kind regards,

*Aragorn*
(Registered GNU/Linux user #223157)