ibv_modify_qp_rate_limit(3) — Linux manual page
IBV_MOD...E_LIMIT(3) Libibverbs Programmer's Manual IBV_MOD...E_LIMIT(3)
NAME
ibv_modify_qp_rate_limit - modify the send rate limits attributes
of a queue pair (QP)
SYNOPSIS
#include <infiniband/verbs.h>
int ibv_modify_qp_rate_limit(struct ibv_qp *qp, struct ibv_qp_rate_limit_attr *attr);
DESCRIPTION
ibv_modify_qp_rate_limit() modifies the send rate limiting packet
pacing attributes of QP qp with the attributes in attr. The
argument attr is an ibv_qp_rate_limit_attr struct, as defined in
<infiniband/verbs.h>.
The rate_limit defines the MAX send rate this QP will send as
long as the link in not blocked and there are work requests in
send queue.
Finer control for shaping the rate limit of a QP is achieved by
defining the max_burst_sz, single burst max bytes size and the
typical_pkt_sz, typical packet bytes size. These allow the device
to adjust the inter-burst gap delay required to correctly shape
the scheduling of sends to the wire in order to reach for
requested application requirements.
Setting a value of 0 for max_burst_sz or typical_pkt_sz will use
the devices defaults. typical_pkt_sz will default to the port's
MTU value.
struct ibv_qp_rate_limit_attr {
uint32_t rate_limit; /* kbps */
uint32_t max_burst_sz; /* bytes */
uint16_t typical_pkt_sz; /* bytes */
};
RETURN VALUE
ibv_modify_qp_rate_limit() returns 0 on success, or the value of
errno on failure (which indicates the failure reason).
ERRORS
EINVAL
Invalid arguments.
EOPNOTSUPP
Function is not implemented for this device. (ENOSYS may
sometimes be returned by old versions of libibverbs).
SEE ALSO
ibv_create_qp(3), ibv_destroy_qp(3), ibv_modify_qp(3),
ibv_query_qp(3)
AUTHORS
Alex Rosenbaum <alexr@mellanox.com>
Bodong Wang <bodong@mellanox.com>
COLOPHON
This page is part of the rdma-core (RDMA Core Userspace Libraries
and Daemons) project. Information about the project can be found
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report for this manual page, send it to
linux-rdma@vger.kernel.org. This page was obtained from the
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⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2024-06-14. (At
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