Project

General

Profile

Idea #7245

Investigate whether we can use an MPI_Barrier to synchronize BoardReaders with a newer version of MPI

Added by Kurt Biery about 6 years ago. Updated over 4 years ago.

Status:
Closed
Priority:
Normal
Assignee:
Category:
-
Target version:
Start date:
10/30/2014
Due date:
% Done:

0%

Estimated time:
80.00 h
Experiment:
-
Duration:

Description

At the moment, we don't have any enforced synchronization between BoardReaders when we are sending fragments. However, there are situations in which it may be nice to have such a thing. (For example, in the demo system when we have multiple BoardReaders.)

Back in the early days of artdaq, MPI_Barrier calls were used to provide this functionality, but they were removed so that we wouldn't get into a situation in which we are trying to end a run, but can't, because one of the BoardReaders is stuck waiting for the others to reach the Barrier but instead have already ended the run.

A possible solution to this dilemma (wanting some level of barrier functionality and wanting to have endRun work reliably) is to use barriers with timeouts. The MPI_Barrier call in the version of MPI that we are currently using does not support a timeout, but I believe that a later version of MPI will have that.

If a new version of MPI is needed, there will probably be spin-off issues for validating the new MPI.


Related issues

Related to artdaq - Feature #10146: Provide moderate synchronization when sending fragments from multiple BoardReadersClosed09/01/2015

History

#1 Updated by Kurt Biery about 5 years ago

  • Target version changed from 577 to v1_12_13

#2 Updated by Kurt Biery about 5 years ago

  • Related to Feature #10146: Provide moderate synchronization when sending fragments from multiple BoardReaders added

#3 Updated by Kurt Biery about 5 years ago

  • Status changed from New to Resolved

This issue was dealt with in Issue #10146.

#4 Updated by Kurt Biery about 5 years ago

  • Assignee set to Kurt Biery

#5 Updated by Eric Flumerfelt over 4 years ago

  • Status changed from Resolved to Closed

Also available in: Atom PDF