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ibv_poll_cq(3) [centos man page]

IBV_POLL_CQ(3)						  Libibverbs Programmer's Manual					    IBV_POLL_CQ(3)

NAME
ibv_poll_cq - poll a completion queue (CQ) SYNOPSIS
#include <infiniband/verbs.h> int ibv_poll_cq(struct ibv_cq *cq, int num_entries, struct ibv_wc *wc); DESCRIPTION
ibv_poll_cq() polls the CQ cq for work completions and returns the first num_entries (or all available completions if the CQ contains fewer than this number) in the array wc. The argument wc is a pointer to an array of ibv_wc structs, as defined in <infiniband/verbs.h>. struct ibv_wc { uint64_t wr_id; /* ID of the completed Work Request (WR) */ enum ibv_wc_status status; /* Status of the operation */ enum ibv_wc_opcode opcode; /* Operation type specified in the completed WR */ uint32_t vendor_err; /* Vendor error syndrome */ uint32_t byte_len; /* Number of bytes transferred */ uint32_t imm_data; /* Immediate data (in network byte order) */ uint32_t qp_num; /* Local QP number of completed WR */ uint32_t src_qp; /* Source QP number (remote QP number) of completed WR (valid only for UD QPs) */ int wc_flags; /* Flags of the completed WR */ uint16_t pkey_index; /* P_Key index (valid only for GSI QPs) */ uint16_t slid; /* Source LID */ uint8_t sl; /* Service Level */ uint8_t dlid_path_bits; /* DLID path bits (not applicable for multicast messages) */ }; The attribute wc_flags describes the properties of the work completion. It is either 0 or the bitwise OR of one or more of the following flags: IBV_WC_GRH GRH is present (valid only for UD QPs) IBV_WC_WITH_IMM Immediate data value is valid Not all wc attributes are always valid. If the completion status is other than IBV_WC_SUCCESS, only the following attributes are valid: wr_id, status, qp_num, and vendor_err. RETURN VALUE
On success, ibv_poll_cq() returns a non-negative value equal to the number of completions found. On failure, a negative value is returned. NOTES
Each polled completion is removed from the CQ and cannot be returned to it. The user should consume work completions at a rate that prevents CQ overrun from occurrence. In case of a CQ overrun, the async event IBV_EVENT_CQ_ERR will be triggered, and the CQ cannot be used. SEE ALSO
ibv_post_send(3), ibv_post_recv(3) AUTHORS
Dotan Barak <dotanba@gmail.com> libibverbs 2006-10-31 IBV_POLL_CQ(3)

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IBV_POST_SRQ_RECV(3)					  Libibverbs Programmer's Manual				      IBV_POST_SRQ_RECV(3)

NAME
ibv_post_srq_recv - post a list of work requests (WRs) to a shared receive queue (SRQ) SYNOPSIS
#include <infiniband/verbs.h> int ibv_post_srq_recv(struct ibv_srq *srq, struct ibv_recv_wr *wr, struct ibv_recv_wr **bad_wr); DESCRIPTION
ibv_post_srq_recv() posts the linked list of work requests (WRs) starting with wr to the shared receive queue (SRQ) srq. It stops process- ing WRs from this list at the first failure (that can be detected immediately while requests are being posted), and returns this failing WR through bad_wr. The argument wr is an ibv_recv_wr struct, as defined in <infiniband/verbs.h>. struct ibv_recv_wr { uint64_t wr_id; /* User defined WR ID */ struct ibv_recv_wr *next; /* Pointer to next WR in list, NULL if last WR */ struct ibv_sge *sg_list; /* Pointer to the s/g array */ int num_sge; /* Size of the s/g array */ }; struct ibv_sge { uint64_t addr; /* Start address of the local memory buffer */ uint32_t length; /* Length of the buffer */ uint32_t lkey; /* Key of the local Memory Region */ }; RETURN VALUE
ibv_post_srq_recv() returns 0 on success, or the value of errno on failure (which indicates the failure reason). NOTES
The buffers used by a WR can only be safely reused after WR the request is fully executed and a work completion has been retrieved from the corresponding completion queue (CQ). If a WR is being posted to a UD QP, the Global Routing Header (GRH) of the incoming message will be placed in the first 40 bytes of the buffer(s) in the scatter list. If no GRH is present in the incoming message, then the first bytes will be undefined. This means that in all cases, the actual data of the incoming message will start at an offset of 40 bytes into the buffer(s) in the scatter list. SEE ALSO
ibv_create_qp(3), ibv_post_send(3), ibv_post_recv(3), ibv_poll_cq(3) AUTHORS
Dotan Barak <dotanba@gmail.com> libibverbs 2006-10-31 IBV_POST_SRQ_RECV(3)
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