On Wed, 2007-02-21 at 23:15 +0100, Andi Kleen wrote: > On Wednesday 21 February 2007 21:52, Jeremy Fitzhardinge wrote: > > Add a set of accessors to pack, unpack and modify page table entries > > (at all levels). This allows a paravirt implementation to control the > > contents of pgd/pmd/pte entries. For example, Xen uses this to > > convert the (pseudo-)physical address into a machine address when > > populating a pagetable entry, and converting back to pphys address > > when an entry is read. > > Do you have some lmbench numbers before/after this change? > iirc at least fork and exit do a lot of pte accesses in various forms. > If it's measurable it might be needed to patch those for the native case. Yes, __mkpte must be patched to avoid performance embarrassment. Jeremy, did you want me to do this, or are you happy to? Rusty. PS. I really must revise my "paravirt-ops counter" patch which tallies how much each op is getting called.
