Invert sense of SLB class bit

David Gibson david at
Wed Sep 7 09:47:02 EST 2005

On Tue, Sep 06, 2005 at 05:03:22PM -0400, Sonny Rao wrote:
> 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? 

Erm.. probably.. although paulus seems to have pushed it already..

David Gibson			| I'll have my music baroque, and my code
david AT	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!

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