[Differential] [Changed Subscribers] D1833: Add memory barriers to buf_ring

ian (Ian Lepore) phabric-noreply at FreeBSD.org
Fri Feb 13 22:27:46 UTC 2015


ian added a subscriber: ian.
ian added a comment.

an atomic_store_rel would put the dmb() before writing the producer ring head, the opposite of what this change proposes (which reinforces my vague feeling that this change isn't quite right somehow).  On the consumer side, it's not clear what piece of data would be the subject of an atomic_load_acq(), because I can't really tell from the current placement of the rmb() what reordering it's trying to prevent.

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

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


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