Ensure all MPI communication to is handled by master thread #3090
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MPI calls have to be done from the *same* thread (`master`) instead of from a `single` thread in MPI_FUNNELED mode according to the specifications.
heplesser
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Feb 5, 2024
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@terhorstd Thank you for this fix. While strictly speaking the resize calls could be done in single, since they do not perform MPI communication, it makes sense to place them in master so we are certain that the buffer data structures always are allocated on the thread performing MPI communication.
mlober
approved these changes
Feb 6, 2024
heplesser
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terhorstd
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T: Bug
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According to the MPI specifications, calls have to be done from the same thread (
master) instead of from asinglethread in MPI_FUNNELED mode . This means a number ofomp singlepragmas needed to be changed toomp master. This should not impact performance overly much, but needs checking!omp master, I added explicit ones where not given anyway.