[v5.0.x] btl,mtl/ofi: set device only flag#13752
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janjust merged 1 commit intoopen-mpi:v5.0.xfrom Apr 15, 2026
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Thanks. I'll test. |
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@aingerson I have tested this patch now, applying it to 5.0.10 and using libfabric 2.4.0 - works as it should. |
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@bwbarrett Is this ok to include in v5.0.x? |
bwbarrett
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Mar 20, 2026
In OFI, the FI_HMEM_DEVICE_ONLY registration flag signals to the provider that the memory is only on the device and is not unified memory (which can migrate between the GPU and host). IPC is only usable with device only memory and is not valid for unified memory. Without this flag, providers cannot provide optimizations like IPC. Set the flag if the address was found to be non-unified memory. This enables IPC copies in OFI. The flag is available starting in v1.13.0 so this adds a configure check to make sure we only use it if available. This also includes an indentation fix and typos within the scope of the patch Cherry-picked from commit e1d8fb8 Signed-off-by: Zach Dworkin <zachary.dworkin@intel.com> Signed-off-by: Alexia Ingerson <alexia.ingerson@intel.com>
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@bwbarrett Thanks for the notes! I've updated to include the cherry pick line that was missing. Sorry about that. |
bwbarrett
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Apr 13, 2026
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In OFI, the FI_HMEM_DEVICE_ONLY registration flag signals to the provider that the memory is only on the device and is not unified memory (which can migrate between the GPU and host). IPC is only usable with device only memory and is not valid for unified memory. Without this flag, providers cannot provide optimizations like IPC. Set the flag if the address was found to be non-unified memory. This enables IPC copies in OFI.
The flag is available starting in v1.13.0 so this adds a configure check to make sure we only use it if available.
This also includes an indentation fix and typos within the scope of the patch