[Differential] [Request, 2 lines] D1833: Add memory barriers to buf_ring

[zbb (Zbigniew Bodek)]

zbb created this revision.
zbb added reviewers: kmacy, rpaulo, imp.
zbb added a subscriber: freebsd-arm.

REVISION SUMMARY
  This issue is mostly the fix for ARMv7 architecture. Make sure
  that memory writes appear in correct order and that the correct
  value is observable on the dequeue side.
  
  Submitted by:   Wojciech Macek <wma at semihalf.com>
  Obtained from: Semihalf

REVISION DETAIL
  https://reviews.freebsd.org/D1833

AFFECTED FILES
  sys/sys/buf_ring.h

To: zbb, kmacy, rpaulo, imp
Cc: freebsd-arm