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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO | AUTHORS | COLOPHON |
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IBV_POST_SRQ_OPS(3) Libibverbs Programmer's Manual IBV_POST_SRQ_OPS(3)
ibv_post_srq_ops - perform on a special shared receive queue (SRQ)
configuration manipulations
#include <infiniband/verbs.h>
int ibv_post_srq_ops(struct ibv_srq *srq, struct ibv_ops_wr *wr,
struct ibv_ops_wr **bad_wr);
The ibv_post_srq_ops() performs series of offload configuration
manipulations on special types of SRQ srq. Currenlty it is used to
configure tag matching SRQ. Series of configuration operations
defined by linked lists of struct ibv_ops_wr elements starting
from wr.
struct ibv_ops_wr {
uint64_t wr_id; /* User defined WR ID */
/* Pointer to next WR in list, NULL if last WR */
struct ibv_ops_wr *next;
enum ibv_ops_wr_opcode opcode; /* From enum ibv_ops_wr_opcode */
int flags; /* From enum ibv_ops_flags */
struct {
/* Number of unexpected messages
* handled by SW */
uint32_t unexpected_cnt;
/* Input parameter for the DEL opcode
* and output parameter for the ADD opcode */
uint32_t handle;
struct {
uint64_t recv_wr_id; /* User defined WR ID for TM_RECV */
struct ibv_sge *sg_list; /* Pointer to the s/g array */
int num_sge; /* Size of the s/g array */
uint64_t tag;
uint64_t mask; /* Incoming message considered matching if
TMH.tag & entry.mask == entry.tag */
} add;
} tm;
};
First part of struct ibv_ops_wr retains ibv_send_wr notion.
Opcode defines operation to perform. Currently supported
IBV_WR_TAG_ADD, IBV_WR_TAG_DEL and IBV_WR_TAG_SYNC values. See
below for detailed description.
To allow reliable data delivery TM SRQ maintains special low level
synchronization primitive - phase synchronization. Receive side
message handling comprises two concurrent activities - posting
tagged buffers by SW and receiving incoming messages by HW. This
process considered coherent only if all unexpected messages
received by HW is completely processed in SW. To pass to hardware
number of processed unexpected messages unexpected_cnt field
should be used and IBV_OPS_TM_SYNC flag should be set.
To request WC for tag list operations IBV_OPS_SIGNALED flags
should be passed. In this case WC will be generated on TM SRQ's
CQ, provided wr_id will identify WC.
Opcode IBV_WR_TAG_ADD used to add tag entry to tag matching list.
Tag entry consists of SGE list, tag & mask (matching parameters),
user specified opaque wr_id (passed via recv_wr_id field) and
uniquely identified by handle (returned by driver). Size of tag
matching list is limited by max_num_tags. SGE list size is
limited by max_sge.
Opcode IBV_WR_TAG_DEL removes previously added tag entry. Field
handle should be set to value returned by previously performed
IBV_WR_TAG_ADD operation. Operation may fail due to concurrent
tag consumption - in this case IBV_WC_TM_ERR status will be
returned in WC.
Opcode IBV_WR_TAG_SYNC may be used if no changes to matching list
required, just to updated unexpected messages counter.
IBV_WC_TM_SYNC_REQ flag returned in list operation WC shows that
counter synchronization required. This flag also may be returned
by unexpected receive WC, asking for IBV_WR_TAG_SYNC operation to
keep TM coherence consistency.
ibv_post_srq_ops() returns 0 on success, or the value of errno on
failure (which indicates the failure reason).
ibv_create_srq_ex(3),
Artemy Kovalyov <[email protected]>
This page is part of the rdma-core (RDMA Core Userspace Libraries
and Daemons) project. Information about the project can be found
at ⟨https://github.com/linux-rdma/rdma-core⟩. If you have a bug
report for this manual page, send it to
[email protected]. This page was obtained from the
project's upstream Git repository
⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2025-08-11. (At
that time, the date of the most recent commit that was found in
the repository was 2025-08-04.) If you discover any rendering
problems in this HTML version of the page, or you believe there is
a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
libibverbs 2017-03-26 IBV_POST_SRQ_OPS(3)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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