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

Christoph Lameter
2008-01-30T19:50:37Z

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;