From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Thu, 10 May 2007 16:29:43 +1000

quoted

We never seemed to reach completion here?

Well, I'm waiting for other people comments too... as I said earlier,
I'm not too fan of burrying the update_mmu_cache() inside
ptep_set_access_flags(), but perhaps we could remove the whole logic of
reading the old PTE & comparing it, and instead have
ptep_set_access_flags() do that locally and return to the caller wether
a change occured that requires update_mmu_cache() to be called.

That way, archs who don't actually need update_mmu_cache() under some
circumstances will be able to return 0 there.

What do you guys thing ?

I think that's a good idea.