[PATCH] powerpc: Fix buglet with MMU hash management

Benjamin Herrenschmidt benh at au1.ibm.com
Tue May 30 14:55:47 EST 2006


On Mon, 2006-05-29 at 23:36 -0500, Olof Johansson wrote:
> On Tue, May 30, 2006 at 02:14:19PM +1000, Benjamin Herrenschmidt wrote:
> 
> > This fixes by allowing the updating of the protection bits in the native
> > hash handling to also set (but not clear) the "C" bit, and, in order to
> > also improve performances in the general case, by always setting that
> > bit on newly inserted hash PTE so that writeback really never happens.
> 
> Good catch!
> 
> However, you'll have a writeback on the R bit too, you should set that
> together with C.

Nope, R is always set at PTE insertion (it's _PAGE_ACCESSED)

Ben.





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