Re: Problem with 1G RAM

David S. Miller (
Fri, 4 Dec 1998 08:08:45 -0800

From: Jakub Jelinek <>
Date: Fri, 4 Dec 1998 10:43:33 +0100 (CET)

Yes, those are 64bit platforms. At least I hope it works well on
sparc64, nobody confirmed it yet (somebody tried it with 2.5GB RAM
though). sparc64 should support up to 1TB physical RAM, but most
of the boxes won't allow you to put that much memory in, AFAIK it
is something around 64GB or so at most one can put in at the


In fact, even sparc32, although PAGE_OFFSET is there 0xf0000000,
should support up to 2GB memory...

Right on sun4m, and you can get away with around 3.5GB on sun4d.
The sun4m limitation is due to the IOMMU, the sun4d case is just a
matter of running out of kernel + user address space. In these
sparc32 cases the PAGE_OFFSET is set dynamically at boot time based
upon how much memory is in the machine.

David S. Miller

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