At 09:38 AM 2/23/2008, Richard Graham wrote:
So I think we are some what talking past each other. I think that what you really care about with respect to communications errors is information on messages that have not completed, and, more important, can't complete ? Is this correct ? I have focused more on errors that occur, but the low-level can handle them and does not need to pass information about them back up to the user. I believe this is where we said that we may want to be able to give the app some indication on performance degradation, at their request. Is this correct ?
Exactly. My point was that the former belongs in the transactional memory API, while the latter belongs in the QoS API. Kannan and I are tasked with drafting something for the latter. One thing to note though is that identical low-level events may fall under either API. In particular, a single-bitflip may result in a message drop in one MPI implementation and a seamless recovery with minor performance degradation in another. The MPI implementation gets to choose the mapping between low-level events and their high-level manifestations. Right now we are just trying to define a reasonable interface for the high-level manifestations. Greg Bronevetsky Post-Doctoral Researcher 1028 Building 451 Lawrence Livermore National Lab (925) 424-5756 [email protected]