User and Reference Guide

Contents

Freeing Communicators

(GLOBAL:COLLECTIVE:COMM_FREE_MISMATCH)
A mistake related to
MPI_Comm_free()
is freeing them in different orders on the involved processes. The MPI standard specifies that
MPI_Comm_free()
must be entered by the processes in the communicator collectively. Some MPIs including Intel® MPI Library deadlock if this rule is broken, whereas others implement
MPI_Comm_free()
as a local call with no communication.
To ensure that this error is detected all the time, Intel® Trace Collector treats
MPI_Comm_free()
just like the other collective operations. There is no special error message for
GLOBAL:COLLECTIVE:COMM_FREE_MISMATCH
, it will be reported as a mismatch between collective calls (
GLOBAL:COLLECTIVE:OPERATION_MISMATCH
) or a deadlock, so
GLOBAL:COLLECTIVE:COMM_FREE_MISMATCH
just refers to the check which enables or disables this test, not a specific error instance.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.