Re: [PATCH 07/13] powerpc: Preemptible mmu_gather

Peter Zijlstra
2010-04-09T09:22:12Z

On Fri, 2010-04-09 at 18:46 +1000, Nick Piggin wrote:
> > struct mmu_page {
> > struct page *page;
> > #ifdef HAVE_ARCH_TLB_VADDR
> > unsigned long vaddr;
> > #endif
> > };
>
> Well you could also have a per-arch struct for this, which they can
> fill in their own info with (I think powerpc takes the pte as well)

Ah, right you are.

Maybe something like:

#ifndef tlb_fill_page
struct mmu_page {
struct page *page;
};

#define tlb_fill_page(tlb, pte, addr) do { } while (0)
#endif

Which can be used from the tlb_remove_tlb_entry() implementation to
gather both the pte and addr. The only complication seems to be that
tlb_remove_tlb_entry() and tlb_remove_page() aren't always matched.

Also, it looks like both power and sparc drive the pte/vaddr flush from
the pte_update/set_pte_at like functions. Which means its not synced to
the mmu_gather at all.

So I'm not at all sure its feasible to link these, but I'll keep it in
mind.