Red Hat Bugzilla – Bug 121805
athlon-smp kernel does not support >4GB of RAM
Last modified: 2007-11-30 17:07:01 EST
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)
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 ***
Changed to 'CLOSED' state since 'RESOLVED' has been deprecated.