Remove support for not creating local MRs #796
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Commits 27548d4 and a1ac0f5 fixed providers that required memory registrations when FI_MR_LOCAL was set, but also broke providers that clear FI_MR_LOCAL (such as HPE's provider), because I did not account for the mr_local handling in the send/recv transport. We don't have a great way to test that case from AWS, the vast majority of transfers will either be HMEM (which creates an MR anyway) or control messages (which have a freelist which creates an MR), and the Libfabric specification allows passing an MR descriptor to a local operation even if the provider clears the FI_MR_LOCAL bit. Therefore, the best path forward seems to be removing the code to skip registration if FI_MR_LOCAL is cleared, and always creating an MR. Signed-off-by: Brian Barrett <bbarrett@amazon.com>
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Created as an alternative to #793, so that we don't trip over this sharp edge again. |
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Thank you for doing that. It works and is a bit improvement over #793. |
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Commits 27548d4 and a1ac0f5 fixed providers that required memory registrations when FI_MR_LOCAL was set, but also broke providers that clear FI_MR_LOCAL (such as HPE's provider), because I did not account for the mr_local handling in the send/recv transport.
We don't have a great way to test that case from AWS, the vast majority of transfers will either be HMEM (which creates an MR anyway) or control messages (which have a freelist which creates an MR), and the Libfabric specification allows passing an MR descriptor to a local operation even if the provider clears the FI_MR_LOCAL bit. Therefore, the best path forward seems to be removing the code to skip registration if FI_MR_LOCAL is cleared, and always creating an MR.
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.