Subject: [RFC PATCH 0/3] couple of TLB flush optimisations

From: Nicholas Piggin <[email-masked]>
Date: Tue, 12 Jun 2018 17:16:18 +1000

I'm just looking around TLB flushing and noticed a few issues with
the core code. The first one seems pretty straightforward, unless I
missed something, but the TLB flush pattern after the revert seems
okay.

The second one might be a bit more interesting for other architectures
and the big comment in include/asm-generic/tlb.h and linked mail from
Linus gives some good context.

I suspect mmu notifiers should use this precise TLB range too, because
I don't see how they could care about the page table structure under
the mapping. Although I only use it in powerpc so far.

Comments?

Thanks,
Nick

Nicholas Piggin (3):
  Revert "mm: always flush VMA ranges affected by zap_page_range"
  mm: mmu_gather track of invalidated TLB ranges explicitly for more
    precise flushing
  powerpc/64s/radix: optimise TLB flush with precise TLB ranges in
    mmu_gather

 arch/powerpc/mm/tlb-radix.c |  7 +++++--
 include/asm-generic/tlb.h   | 27 +++++++++++++++++++++++++--
 mm/memory.c                 | 18 ++++--------------
 3 files changed, 34 insertions(+), 18 deletions(-)

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2.17.0