mm/mmu_notifier: avoid call to invalidate_range() in range_end()

This is an optimization patch that only affect mmu_notifier users which
rely on the invalidate_range() callback.  This patch avoids calling that
callback twice in a row from inside __mmu_notifier_invalidate_range_end

Existing pattern (before this patch):
    mmu_notifier_invalidate_range_start()
        pte/pmd/pud_clear_flush_notify()
            mmu_notifier_invalidate_range()
    mmu_notifier_invalidate_range_end()
        mmu_notifier_invalidate_range()

New pattern (after this patch):
    mmu_notifier_invalidate_range_start()
        pte/pmd/pud_clear_flush_notify()
            mmu_notifier_invalidate_range()
    mmu_notifier_invalidate_range_only_end()

We call the invalidate_range callback after clearing the page table
under the page table lock and we skip the call to invalidate_range
inside the __mmu_notifier_invalidate_range_end() function.

Idea from Andrea Arcangeli

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jérôme Glisse <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Suravee Suthikulpanit <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Andrew Donnellan <[email protected]>
Cc: Nadav Amit <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions