Re: PAE (was: Debian Gnome Or XFCE ?)

[Stephen Powell <zlinuxman@wowway.com>]

On Tue, 25 Aug 2015 01:43:50 -0400 (EDT), Tixy wrote:
> 
> Wikipedia, that font of all wisdom, says of NX [1]
> ...
> [1] https://en.wikipedia.org/wiki/NX_bit

>From that same article, the section on the Linux kernel says this:
> 
> The support for this feature in the 64-bit mode on x86-64 CPUs was
> added in 2004 by Andi Kleen, and later the same year, Ingo Molnar
> added support for it in 32-bit mode on 64-bit CPUs.  These features
> have been in the stable Linux kernel since release 2.6.8 in August 2004.
> 
> The availability of the NX bit on 32-bit x86 kernels, which may run
> on both 32-bit x86 CPUs and 64-bit x86 compatible CPUs, is significant
> because a 32-bit x86 kernel would not normally expect the NX bit that
> an x86-64 processor supplies; the NX enabler patch ensures that these
> kernels will attempt to use the NX bit if present.

So it looks like you're right.  The NX feature can be used only when
running a 32-bit kernel in PAE mode on a 64-bit processor.  When running
a 32-bit kernel in PAE mode on a 32-bit processor, the NX bit is not
available.  So I'm back to my original question.  For a system with a
32-bit processor and less than 4G of RAM, what does running a PAE kernel
buy me?  I can understand why commercial Linux distributions want to
eliminate a non-PAE kernel: it's one less kernel to support, and therefore
higher profits.  But what does running a PAE kernel on a 32-bit system
with less than 4G of RAM do for *me*?  All I see it doing is making the
kernel bigger and chewing up more RAM.

-- 
  .''`.     Stephen Powell    <zlinuxman@wowway.com>
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