Switching Fedora to pae kernel by default?

[Jeremy Katz]

On Monday, January 19 2009, Bill Nottingham said:
> Dave Jones (davej at redhat.com) said: 
> > On Mon, Jan 19, 2009 at 03:49:20PM +0200, Avi Kivity wrote:
> >  > This probably comes up once in a while, thought I'd raise it again.
> >  > 
> >  > I'd like to suggest switching the default kernel to -PAE on machines 
> >  > that support it, for the following reasons:
> >  > 
> >  > - many machines have 4GB+ these days, even desktops
> >  > - NX is only available with -PAE, improves security
> >  > - kvm is significantly faster on AMD when PAE is selected (since we 
> >  > don't support NPT on non-PAE)
> > 
> > What's needed to set this by default is changes in anaconda.
> > They have their own list at anaconda-list at redhat.com
> 
> anaconda-devel-list, actually. But I could have sworn we already did this.

Well, we're not going to make the change unless kernel guys want us to. 

That said, we currently do install the PAE kernel if you have 4 GB+ of
RAM[1].  Switching to it by default is problematic because then we're
back to using different kernels for different cases and it also makes
the 'what do you with the live image' case a lot more complex.

The _real_ fix here is to get PAE runtime much like was finally done
with SMP :-)

Jeremy

[1] Well, any memory above 4 GB actually -- so if you have a machine
with a large hole and only 3 GB of RAM, you could end up with the PAE
kernel