1IBV_MODIFY_QP_RATE_LIMIT(L3i)bibverbs Programmer's ManuIaBlV_MODIFY_QP_RATE_LIMIT(3)
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NAME

6       ibv_modify_qp_rate_limit  - modify the send rate limits attributes of a
7       queue pair (QP)
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SYNOPSIS

10       #include <infiniband/verbs.h>
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12       int ibv_modify_qp_rate_limit(struct ibv_qp *qp, struct ibv_qp_rate_limit_attr *attr);
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DESCRIPTION

15       ibv_modify_qp_rate_limit() modifies the send rate limiting packet  pac‐
16       ing attributes of QP qp with the attributes in attr.  The argument attr
17       is  an  ibv_qp_rate_limit_attr   struct,   as   defined   in   <infini‐
18       band/verbs.h>.
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20       The  rate_limit  defines the MAX send rate this QP will send as long as
21       the link in not blocked and there are work requests in send queue.
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23       Finer control for shaping the rate limit of a QP is achieved by  defin‐
24       ing  the  max_burst_sz,  single  burst  max  bytes  size  and the typi‐
25       cal_pkt_sz, typical packet bytes size. These allow the device to adjust
26       the inter-burst gap delay required to correctly shape the scheduling of
27       sends to the wire in order to reach for requested application  require‐
28       ments.
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30       Setting  a  value  of 0 for max_burst_sz or typical_pkt_sz will use the
31       devices defaults.  typical_pkt_sz will default to the port's MTU value.
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33       struct ibv_qp_rate_limit_attr {
34               uint32_t        rate_limit;     /* kbps */
35               uint32_t        max_burst_sz;   /* bytes */
36               uint16_t        typical_pkt_sz; /* bytes */
37       };
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RETURN VALUE

40       ibv_modify_qp_rate_limit() returns 0 on success, or the value of  errno
41       on failure (which indicates the failure reason).
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ERRORS

44   EINVAL
45       Invalid arguments.
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47   EOPNOTSUPP
48       Function  is not implemented for this device.  (ENOSYS may sometimes be
49       returned by old versions of libibverbs).
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SEE ALSO

52       ibv_create_qp(3), ibv_destroy_qp(3), ibv_modify_qp(3), ibv_query_qp(3)
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AUTHORS

55       Alex Rosenbaum <alexr@mellanox.com>
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57       Bodong Wang <bodong@mellanox.com>
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61libibverbs                        2018-01-09       IBV_MODIFY_QP_RATE_LIMIT(3)
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