Messages in this thread | | | Date | Wed, 27 May 2015 10:33:43 -0400 | From | Jerome Glisse <> | Subject | Re: [PATCH 03/36] mmu_notifier: pass page pointer to mmu_notifier_invalidate_page() |
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On Wed, May 27, 2015 at 10:47:44AM +0530, Aneesh Kumar K.V wrote: > j.glisse@gmail.com writes: > > > From: Jérôme Glisse <jglisse@redhat.com> > > > > Listener of mm event might not have easy way to get the struct page > > behind and address invalidated with mmu_notifier_invalidate_page() > > function as this happens after the cpu page table have been clear/ > > updated. This happens for instance if the listener is storing a dma > > mapping inside its secondary page table. To avoid complex reverse > > dma mapping lookup just pass along a pointer to the page being > > invalidated. > > ..... > > > diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h > > index ada3ed1..283ad26 100644 > > --- a/include/linux/mmu_notifier.h > > +++ b/include/linux/mmu_notifier.h > > @@ -172,6 +172,7 @@ struct mmu_notifier_ops { > > void (*invalidate_page)(struct mmu_notifier *mn, > > struct mm_struct *mm, > > unsigned long address, > > + struct page *page, > > enum mmu_event event); > > > > How do we handle this w.r.t invalidate_range ?
With range invalidation the CPU page table is still reliable when invalidate_range_start() callback happen. So we can lookup the CPU page table to get the page backing the address.
Cheers, Jérôme
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