Re: One (possible) x86 get_user_pages bug

[Peter Zijlstra]

On Thu, 2011-01-27 at 10:27 -0800, Jeremy Fitzhardinge wrote:
> 
> So is there some way we can preserve the current scheme's benefits while
> making it a bit more general?  (If anyone else has non-IPI-based
> shootdown, it would be s390; is there some inspiration there?  An
> instruction perhaps?) 

Well, you can provide a xen gupf implementation based on rcu freed
page-tables like powerpc, sparc and s390 have.

But you'll have to change the mmu_gather implementation of xen and use
the get_page_unless_zero() thing mentioned before (or use
page_cache_get_speculative()).

But I see no need to change the x86 implementation, if the architecture
ever changes the way it does tlb invalidation we need to change more
than just the gupf implementation.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/