Bug 121805 - athlon-smp kernel does not support >4GB of RAM
Summary: athlon-smp kernel does not support >4GB of RAM
Status: CLOSED DUPLICATE of bug 12801
Alias: None
Product: Red Hat Enterprise Linux 3
Classification: Red Hat
Component: kernel
Version: 3.0
Hardware: athlon
OS: Linux
Target Milestone: ---
Assignee: Arjan van de Ven
QA Contact: Brian Brock
Depends On:
TreeView+ depends on / blocked
Reported: 2004-04-27 23:19 UTC by Duncan Laurie
Modified: 2007-11-30 22:07 UTC (History)
2 users (show)

Clone Of:
Last Closed: 2006-02-21 19:02:48 UTC

Attachments (Terms of Use)

Description Duncan Laurie 2004-04-27 23:19:37 UTC
In order to support between 4GB and 16GB of RAM in 32-bit mode
on an opteron system the kernel needs to be compiled with
the CONFIG_HIGHMEM64G option enabled.

From what I can gather, the -smp kernels should be compiled with
PAE + highpte support by enabling the CONFIG_HIGHMEM64G option,
which will also enable CONFIG_X86_PAE.  Then the -hugemem kernel
should support PAE + highpte + 4/4 split by enabling the
CONFIG_HIGHMEM64G and the CONFIG_X86_4G options.
(see the posting by Rik van Riel about this: http://www.redhat.

Currently the i686-smp kernel has the HIGHMEM64G option enabled
while the athlon-smp kernel only has HIGHMEM4G enabled.  This means
it is possible to use the i686-smp kernel to run opteron system with
between 4GB and 16GB in 32-bit mode and use the hugemem kernel
on systems with >16GB.

However it seems that the athlon-smp kernel should also be compiled
with the CONFIG_HIGHMEM64G option so it looks and acts the same as
the i686-smp variant.

Steps to Reproduce:
1. Install >4GB RAM in an opteron system
2. Install and boot kernel-smp-2.4.21-9.0.3.EL.athlon.rpm

Actual Results:  recognized RAM is limited to 4GB
Expected Results:  all available RAM is recognized (up to 16GB)

Comment 1 Duncan Laurie 2004-04-27 23:35:31 UTC
I must have hit reload in the submit window for this to come
through twice.  Closing the dup...

*** This bug has been marked as a duplicate of 12801 ***

Comment 2 Red Hat Bugzilla 2006-02-21 19:02:48 UTC
Changed to 'CLOSED' state since 'RESOLVED' has been deprecated.

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