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The thread/process would include the MR rkey in the data passed to post_send() and configure the sge list with MR lkey to transfer from.

I am playing with infiniband HW and wanted to check if it was legal to have MR using lkey and rkey by the same thread sending and receiving RDMAs locally.

SFbay007
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1 Answers1

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I'm not sure if I understand the question, but yes it is perfectly OK to use both the L_Key and R_Key of the same MR for local requests. You may get strange results if you use overlapping memory for a work request to send from and receive into — for example RDMA WRITE of 100 bytes taken from address X into address X + 50. Similarly having multiple work requests in flight where one is overwriting the same memory used by another one will lead to confusing results.

However doing, say, RDMA WRITE of 100 bytes from local address X to local address X + 200 (where those addresses are in the same memory region) is perfectly fine -- you are just using your RDMA adapter as a fancy local DMA engine.

Roland
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