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Date: Fri, 10 Oct 2003 19:53:31 +0200
From: Ralf Baechle <ralf@linux-mips.org>
To: Krishna Kondaka <Krishna.Kondaka@MCDATA.com>
Cc: linux-mips@linux-mips.org
Subject: Re: mips 32 bit HIGHMEM support
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On Fri, Oct 10, 2003 at 10:44:19AM -0700, Krishna Kondaka wrote:

> How safe is it to enable HIGHMEM for sibyte/broadcom's BCM12500 processors?
> Do you know if any one is using HIGHMEM enabled linux on BCM12500s?

Perfectly reliable - in fact highmem for MIPS was written and debugged
on this chip but there are many other that will work just as fine since
they share the technical properties required to run highmem.

Actually with the latest change in CVS enabling CONFIG_HIGHMEM is always
safe; in cases where it's not safe the kernel will simply limit the
memory it's using to just lowmem.

Stil the usual warning applies - highmem is a kludge and for systems
doing heavy I/O it can be a rather slow kludge.  64-bit is the Nirvana
kernel hackers are seeking ;-)

  Ralf