Hi all, On 12/18/2013 05:09 PM, Marc-Andre Hermanns wrote:
Hi Jeff,
as a tools provider I would also like MPI_T to expose other sensors, as this means I don't have to support yet another metric interface. Not stacking a multitude of different metric interfaces on top of each other might also cut down on the overhead as you said.
Coming from the same tools group I unfortunately have to disagree with Marc-Andre on that. Most of the tools out there (if not all relevant for HPC) already have good support for PAPI, which does a great job of providing a portable API to counters of all kind. And it's not an easy job to do, so I'm not sure every MPI implementation would want to copy that work. And that would be necessary if we'd only want to use MPI_T as a single counter source, otherwise we'd still have to maintain both (in fact, we'd for sure have to, as there are other parallel programming paradigms out there as well which tools have to support). So what I'd prefer is a PAPI component exposing the MPI relevant counters via PAPI, that way the tools could benefit from that with very little additional work.
But could an implementation not expose such info right now? I thought the whole idea of not standardizing anything about counters, their names and semantics, is that implementations can expose whatever they care about.
Here I agree, from what I read in the current standard the interface doesn't guarantee me anything. So at least some kind of high-level/low-level interface as in PAPI would certainly be desirable. -Michael -- Michael Knobloch Institute for Advanced Simulation (IAS) Jülich Supercomputing Centre (JSC) Telefon: +49 2461 61-3546 Telefax: +49 2461 61-6656 E-Mail: [email protected] Internet: http://www.fz-juelich.de/jsc ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDir Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------