PAE versus HIGHMEM64

[Thorsten Leemhuis]

On 16.09.2007 20:14, Chris Lalancette wrote:
> Thorsten Leemhuis wrote:
>> Which brings me to the point why I'm writing this mail: should we enable
>> PAE by default after F8 is out and ship a HIGHMEM64G-Kernel instead on
>> x86-32? Then normal users on x86-32 can benefit from NX by default. Or
>> is that considered "not worth the trouble because we ship execshield
>> already"?
>>
>> Further: Does PAE-by-default still make lots of machines unbootable (I
>> doubt that for newer machines, as some-well-known-other-os enables PAE
>> since its service pack 2 by default iirc)? If we suspect it still does:
>> could we fix that by some kind of automatic "if machine is newer than
>> ${year}" check in the kernel?
>>
>> Just wondering.
> 
> Yes, it does still tend to break machines,

:-/ -- as expected... Nevertheless thx for sharing your experiences.

> [...] Unfortunately, PAE is a compile time option, not 
> something that can (currently) be turned on or off at runtime.  It would 
> be nice to make it a runtime option (IIRC, OpenSolaris does this), but I 
> don't know if it is worth the effort given that 32-bit should be 
> becoming less and less common.

Agreed -- but on the other hand x86-32 still is quite famous even on
x86-64 machines. Well, sooner or later that should change :-)

Cu
knurd