Invert sense of SLB class bit

[Sonny Rao]

On Tue, Sep 06, 2005 at 02:59:47PM +1000, David Gibson wrote:
> Currently, we set the class bit in kernel SLB entries, and clear it on
> user SLB entries.  On POWER5, ERAT entries created in real mode have
> the class bit clear.  So to avoid flushing kernel ERAT entries on each
> context switch, this patch inverts our usage of the class bit, setting
> it on user SLB entries and clearing it on kernel SLB entries.
> 
> Booted on POWER5 and G5.

Hmm, do you think it is worth doing an SDET (or something ) comparison
w/ and w/out this patch? 

Sonny