Hi Marc-Andre, The idea is that the implementation may be instrumented with the ability to record timestamped events. Like the "variable" interface, the idea here is to provide a way to expose whatever the implementation is prepared to make available, such as information that the developers and tuners of that implementation have found valuable. So in answer to your questoins: 1) what will be logged? Probably timestamps, some indication of location, and some context (like message length). I would not expect all routine parameters to be logged, though an implementation could choose to do thiat 2) it is lightweight for two reasons: (1) the data logged may be as small and simple as the implementation chooses and (2) the data may be logged in an internal, time and space efficient format. A separate set of routines are provided to interpret the logged data. For example, the timestamps may be stored in an internal format (such as the bits from a clock register) and converted to seconds only when the user evaluates the logged data. 3) A performance tool can examine the log files but (as part of the light-weight part) there is no option to invoke a method or routine at every point a log record could be created. "Users" here means users with some degree of sophistication. Basically, if you can use PAPI and really understand what the various counters mean, then you should be able to use this interface. Bill On Jun 29, 2009, at 7:42 AM, Marc-Andre Hermanns wrote:

Hi Martin,

I am interested in how this logging facility is meant. Do you have a more detailed description of it somewhere?

- What do you anticipate to be logged (despite of timestamps)? - What will make it lightweight? - Is there any way that a performance tool might hook into?

"[...] Users can then read and evaluate this event log at a later time. [...]"

Who are these users? Application developers or tool developers?

Best regards, Marc-Andre

Martin Schulz wrote:

...

Hi all,

As discussed during the last meeting, our next MPI 3 tools WG TelCon is on 6/29 at the usual time (8am PDT, 11am EDT, 5pm MSZ). The dial-in numbers are as usual:

* Toll Free Dial In Number for Offsite Participants: 866-914-3976 * International Access/Caller Paid Dial In Number: 925-424-8105 * Dial In Number for LLNL Onsite Participants: 4-8105 * Access Security Code: 860609 #

So far, the agenda is to talk about a proposal for a general performance information interface. More information on this proposal is at:

https://svn.mpi-forum.org/trac/mpi-forum-web/wiki/MPI3Tools/pimpi

If anybody wants to bring up another agenda item, please let me know.

Martin

_______________________________________________________________________ Martin Schulz, [email protected], http:// people.llnl.gov/schulz6 CASC @ Lawrence Livermore National Laboratory, Livermore, USA

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