1mlx5dv_map_ah_to_qp(3)                                  mlx5dv_map_ah_to_qp(3)
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NAME

6       mlx5dv_map_ah_to_qp  -  Map the destination path information in address
7       handle (AH) to the information extracted from the qp.
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SYNOPSIS

10              #include <infiniband/mlx5dv.h>
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12              int mlx5dv_map_ah_to_qp(struct ibv_ah *ah, uint32_t qp_num);
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DESCRIPTION

15       This API maps the destination path information in address  handle  (ah)
16       to  the information extracted from the qp (e.g. congestion control from
17       ECE).
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19       This API serves as an enhancement to DC and UD QPs  to  achieve  better
20       performance  by  using  per-address congestion control (CC) algorithms,
21       enabling DC/UD QPs to use multiple CC algorithms in the  same  datacen‐
22       ter.
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24       The  mapping  created  by this API is implicitly destroyed when the ad‐
25       dress handle is destroyed.  It is not affected by the destruction of QP
26       qp_num.
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28       A duplicate mapping to the same address handle is ignored.  As this API
29       is just a hint for the hardware in this case it would  do  nothing  and
30       return success regardless of the new qp_num ECE.
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32       The  function must be called after ECE negotiation/preconfiguration was
33       done by some external means.
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ARGUMENTS

36       ah     The target’s address handle.
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38       qp_num The initiator QP from which congestion  control  information  is
39              extracted from its ECE.
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RETURN VALUE

42       Upon success, returns 0; Upon failure, the value of errno is returned.
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SEE ALSO

45       rdma_cm(7), rdma_get_remote_ece(3), ibv_query_ece(3), ibv_set_ece(3)
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AUTHOR

48       Yochai Cohen <yochai@nvidia.com>
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50       Patrisious Haddad <phaddad@nvidia.com>
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54                                                        mlx5dv_map_ah_to_qp(3)