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Updated: Thursday, June 13, 2019
 
 

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

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.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+-----------------------+
       |ATTRIBUTE TYPE |   ATTRIBUTE VALUE     |
       +---------------+-----------------------+
       |Availability   | network/open-fabrics  |
       +---------------+-----------------------+
       |Stability      | Pass-through volatile |
       +---------------+-----------------------+
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>


              This    software    was   built   from   source   available   at
              https://github.com/oracle/solaris-userland.  The original commu-
              nity   source   was   downloaded   from   ['https://www.openfab-
              rics.org/downloads/ibutils/ibutils-1.5.7-0.2.gbd7e502.tar.gz',
              'https://www.openfabrics.org/downloads/libibverbs/libib-
              verbs-1.1.8.tar.gz',          'https://www.openfabrics.org/down-
              loads/libmlx4/libmlx4-1.0.6.tar.gz',       'https://www.openfab-
              rics.org/downloads/libsdp/libsdp-1.1.108-0.15.gd7fdb72.tar.gz',
              'https://www.openfabrics.org/downloads/management/infiniband-
              diags-1.6.5.tar.gz', 'https://www.openfabrics.org/downloads/man-
              agement/libibmad-1.3.12.tar.gz',           'https://www.openfab-
              rics.org/downloads/management/libibumad-1.3.10.2.tar.gz',
              'https://www.openfabrics.org/downloads/manage-
              ment/opensm-3.3.19.tar.gz',   'https://www.openfabrics.org/down-
              loads/perftest/perftest-1.3.0-0.42.gf350d3d.tar.gz',
              'https://www.openfabrics.org/down-
              loads/qperf/qperf-0.4.9.tar.gz',           'https://www.openfab-
              rics.org/downloads/rdmacm/librdmacm-1.0.21.tar.gz',
              'https://www.openfabrics.org/downloads/rds-tools/rds-
              tools-2.0.4.tar.gz']

              Further information about this software can be found on the open
              source community website at http://www.openfabrics.org/.



libibverbs                        2006-10-31                    IBV_POLL_CQ(3)