Re: [kvm-devel] [patch 2/6] mmu_notifier: Callbacks to invalidate address ranges

Andrea Arcangeli
2008-01-31T13:39:29Z

On Wed, Jan 30, 2008 at 06:51:26PM -0800, Christoph Lameter wrote:
> True. hlist_del_init ok? That would allow to check the driver that the
> mmu_notifier is already linked in using !hlist_unhashed(). Driver then
> needs to properly initialize the mmu_notifier list with INIT_HLIST_NODE().

A driver couldn't possibly care about the mmu notifier anymore at that
point, we just agreed a moment ago that the list can't change under
mmu_notifier_release, and in turn no driver could possibly call
mmu_notifier_unregister/register at that point anymore regardless of
the outcome of hlist_unhashed and external serialization must let the
driver know he's done with the notifiers.