Some multi-threading fixes #9302
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The second commit looks larger than it really is, it is mostly spacing adjustments. |
| /** | ||
| * Register and open all available components, giving them a chance to access the MCA parameters. | ||
| */ | ||
| OPAL_THREAD_LOCK(&ompi_mpi_topo_bootstrap_mutex); |
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I would rather have this safety moved down into the framework itself, as I don't think that any lazily initialized framework support, or need, to allow threaded initialization.
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Can you expand on this a bit? The io framework lazy init does something similar to what's done here.
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As you mentionned we have several frameworks that need to be initialized lazily potentially in a multi-threaded way. I would like to have a consistent way to handle their lazy initialization, to avoid any discrepancies between them.
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I opened #9307 for discussing the lazy framework initialization. I can work on that once we have consensus. We can remove this specific commit from the PR, so that the rest needn't be held up.
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Thanks @nysal . Will remove the commit.
…on after wait completes. We found an issue where with using multiple threads, it is possible for the data to not be in the buffer before MPI_Wait() returns. Testing the buffer later after MPI_Wait() returned would show the data arrives eventually without the rmb(). We have seen this issue on Power9 intermittently using PAMI, but in theory could happen with any transport. Signed-off-by: Austen Lauria <awlauria@us.ibm.com>
Signed-off-by: Austen Lauria <awlauria@us.ibm.com>
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Removed the commit with the topo changes. |
ompi/request: Add a read memory barrier to sync the receive buffer so…
…on after wait completes.
We found an issue where with using multiple threads, it is possible for the data
to not be in the buffer before MPI_Wait() returns. Testing the buffer later after
MPI_Wait() returned would show the data arrives eventually without the rmb().
We have seen this issue on Power9 intermittently using PAMI, but in theory could
happen with any transport.
Signed-off-by: Austen Lauria awlauria@us.ibm.com