Tpetra::CrsMatrix::globalAssemble: Purge unnecessary barriers
Created by: mhoemmen
@trilinos/tpetra
There are two unnecessary barriers after waitAll in Tpetra::CrsMatrix::globalAssemble. It should be possible to purge these barriers, for the following reasons:
- The reduceAll at the start of the method precludes reëntrant calls that would mix up message tags.
- If we want to be cautious about tags, we may take Distributor's approach, and specify distinct tags for each of the two rounds of point-to-point communication.