On Monday 25 November 2002 10:53, Ryland Bingham wrote:
> I'm getting ready to build a monster. I've got an IBM x360 with four
> 2.0GHZ zeon MP's, with 8GB of memory. Does anybody know how much Memory
> is Addressable by default with the 2.4.19 kernel?
Physical Memory addressible using PAE mode: 64G
Virtual Memory addressable by any running process: 4G
While physical memory can be accessed in 36bits, the process space still
remains 32bit. While the kernel can change its process space to access the
extra RAM as it needs to, a process cannot - it is effectively limited to 3G
(from the 3G/1G split of the 4G addressable 32bit space).
> I think I read that there is support for 36bit addressing, but is this a
> patch or an option when I make the kernel? I'm going to be installing
> RH 8.0 and then replacing with a generic kernel + a patch for SMP
> control. Any body have experience in building large machines?
You want a kernel built with PAE support (CONFIG_HIGHMEM64G).
"36bit addressing" is offered by the Intel PAE mode memory access. It's an
option that you set when building your kernel. It does impose a 3-6% speed
penalty, but you get to use that precious RAM ;)
I believe there is a "RedHat 8.0 Enterprise" version that has kernels prebuilt
with larger memory models.
-- - Ian C. Blenke <icblenke@nks.net>(This message bound by the following: http://www.nks.net/email_disclaimer.html)
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