We recently had to debug a TLB invalidation problem on the munmap()
path, which was made more difficult than necessary because:

  (a) The MMU gather code had changed without people realising
  (b) Many people subtly misunderstood the operation of the MMU gather
      code and its interactions with RCU and arch-specific TLB invalidation
  (c) Untangling the intended behaviour involved educated guesswork and
      plenty of discussion

Hopefully, we can avoid getting into this mess again by designating a
cross-arch group of people to look after this code. It is not intended
that they will have a separate tree, but they at least provide a point
of contact for anybody working in this area and can co-ordinate any
proposed future changes to the internal API.

Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Nicholas Piggin <npig...@gmail.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: "Aneesh Kumar K.V" <aneesh.ku...@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Michal Hocko <mho...@suse.com>
Signed-off-by: Will Deacon <will.dea...@arm.com>
---
 MAINTAINERS | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 9ad052aeac39..e490a0a0605a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9681,6 +9681,18 @@ S:       Maintained
 F:     arch/arm/boot/dts/mmp*
 F:     arch/arm/mach-mmp/
 
+MMU GATHER AND TLB INVALIDATION
+M:     Will Deacon <will.dea...@arm.com>
+M:     "Aneesh Kumar K.V" <aneesh.ku...@linux.vnet.ibm.com>
+M:     Nick Piggin <npig...@gmail.com>
+M:     Peter Zijlstra <pet...@infradead.org>
+L:     linux-a...@vger.kernel.org
+L:     linux...@kvack.org
+S:     Maintained
+F:     arch/*/include/asm/tlb.h
+F:     include/asm-generic/tlb.h
+F:     mm/mmu_gather.c
+
 MN88472 MEDIA DRIVER
 M:     Antti Palosaari <cr...@iki.fi>
 L:     linux-me...@vger.kernel.org
-- 
2.1.4

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