Call ibv_post_send twice on the same QP on the same CX7 NIC, the latter does not work

Infrastructure & Networking Software And Drivers Mellanox OFED
1

I was trying to call ibv_post_send multiple times on CX7. Most of the setting are the same:

  • I used the same QP,
  • the QP state was not changed between these two calles,
  • the parameters for ibv_post_send is almost the same, except for the memory address and local key.

But the second ibv_post_send call never seems to work. It returns 0, but no packet is generated.
Interestingly, CX-5 does not have this problem, only CX-7 has. Are there specific settings for this to work on CX-7?

2

Hi mayaxuan,
Could you try setting the MegReq bit as 0 in the packet?
By the way, I see a similar case in the NVIDIA Enterprise Support system. Do you submit that?
If so, continue to solve the issue with our RDMA engineer in the NVIDIA Enterprise Support system.

Good Luck

3

Yes, it was solved by setting MigReg to 0. Thanks