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

[Christoph Lameter]

On Wed, 30 Jan 2008, Andrea Arcangeli wrote:

> XPMEM requires with invalidate_range (sleepy) +
> before_invalidate_range (sleepy). invalidate_all should also be called
> before_release (both sleepy).
> 
> It sounds we need full overlap of information provided by
> invalidate_page and invalidate_range to fit all three models (the
> opposite of the zero objective that current V3 is taking). And the
> swap will be handled only by invalidate_page either through linux rmap
> or external rmap (with the latter that can sleep so it's ok for you,
> the former not). GRU can safely use the either the linux rmap notifier
> or the external rmap notifier equally well, because when try_to_unmap
> is called the page is locked and obviously pinned by the VM itself.

So put the invalidate_page() callbacks in everywhere.

Then we have 

invalidate_range_start(mm)

and

invalidate_range_finish(mm, start, end)

in addition to the invalidate rmap_notifier?

---
 include/linux/mmu_notifier.h |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Index: linux-2.6/include/linux/mmu_notifier.h
===================================================================
--- linux-2.6.orig/include/linux/mmu_notifier.h	2008-01-30 11:49:02.000000000 -0800
+++ linux-2.6/include/linux/mmu_notifier.h	2008-01-30 11:49:57.000000000 -0800
@@ -69,10 +69,13 @@ struct mmu_notifier_ops {
 	/*
 	 * lock indicates that the function is called under spinlock.
 	 */
-	void (*invalidate_range)(struct mmu_notifier *mn,
+	void (*invalidate_range_begin)(struct mmu_notifier *mn,
 				 struct mm_struct *mm,
-				 unsigned long start, unsigned long end,
 				 int lock);
+
+	void (*invalidate_range_end)(struct mmu_notifier *mn,
+				 struct mm_struct *mm,
+				 unsigned long start, unsigned long end);
 };
 
 struct mmu_rmap_notifier_ops;
--
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