Re: [RFC][PATCH v3 1/6] mm: Don't unmap gup()ed page

From: KOSAKI Motohiro
Date: Wed Apr 15 2009 - 07:53:24 EST


>> Can we assume mmu_notifier is only used by kvm now?
>> if not, we need to make new notifier.
>
> KVM is no fundamentally different from other users in this respect, so
> I don't see why need a new notifier. If it works for others it'll work
> for KVM and the other way around is true too.
>
> mmu notifier users can or cannot take a page pin. KVM does. GRU
> doesn't. XPMEM does. All of them releases any pin after
> mmu_notifier_invalidate_page. All that is important is to run
> mmu_notifier_invalidate_page _after_ the ptep_clear_young_notify, so
> that we don't nuke secondary mappings on the pages unless we really go
> to nuke the pte.

Thank you kindful explain. I understand it :)
--
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/