[ofiwg] libfabric network atomic operations, processor atomic ops, and coherence

[Greg Titus]

> On Feb 26, 2019, at 12:31 PM, Hefty, Sean <sean.hefty at intel.com> wrote:
> 
> Copying ofiwg
> 
>> ...  What can a
>> programmer using libfabric atomics assume about coherence between network and
>> processor atomic operations [?]
> 
> There is no guarantee that NIC/network based atomics will be coherent with CPU based atomics, or that they will be coherent between NICs, or the final result will even be atomic.  [...]

Would I be correct in reading that last clause as “or [that] the [visibility of the] final result will even be atomic”, meaning that visibility of one subpart (byte, for example) of the result should not be taken as evidence of visibility of the whole?  Or in other words, that the paragraph about CPU visibility provides the only guarantees of visibility.  (So if tearing occurs, it will have been dealt with before that guaranteed-visible point.)

thanks,
greg