IBV_CREATE_CQ_EX(3) Libibverbs Programmer's Manual IBV_CREATE_CQ_EX(3)
NAME
ibv_create_cq_ex - create a completion queue (CQ)
SYNOPSIS
#include <infiniband/verbs.h>
struct ibv_cq_ex *ibv_create_cq_ex(struct ibv_context *context,
struct ibv_create_cq_attr_ex *cq_attr);
DESCRIPTION
ibv_create_cq_ex() creates a completion queue (CQ) for RDMA device
context context. The argument cq_attr is a pointer to struct
ibv_cq_init_attr_ex as defined in <infiniband/verbs.h>.
struct ibv_cq_init_attr_ex {
int cqe; /* Minimum number of entries required for CQ */
void *cq_context; /* Consumer-supplied context returned for completion events */
struct ibv_comp_channel *channel; /* Completion channel where completion events will be queued. May be NULL if completion events will not be used. */
int comp_vector; /* Completion vector used to signal completion events. Must be >= 0 and < context->num_comp_vectors. */
uint64_t wc_flags; /* The wc_flags that should be returned in ibv_poll_cq_ex. Or'ed bit of enum ibv_wc_flags_ex. */
uint32_t comp_mask; /* compatibility mask (extended verb). */
uint32_t flags /* One or more flags from enum ibv_create_cq_attr_flags */
};
enum ibv_wc_flags_ex {
IBV_WC_EX_WITH_BYTE_LEN = 1 << 0, /* Require byte len in WC */
IBV_WC_EX_WITH_IMM = 1 << 1, /* Require immediate in WC */
IBV_WC_EX_WITH_QP_NUM = 1 << 2, /* Require QP number in WC */
IBV_WC_EX_WITH_SRC_QP = 1 << 3, /* Require source QP in WC */
IBV_WC_EX_WITH_SLID = 1 << 4, /* Require slid in WC */
IBV_WC_EX_WITH_SL = 1 << 5, /* Require sl in WC */
IBV_WC_EX_WITH_DLID_PATH_BITS = 1 << 6, /* Require dlid path bits in WC */
IBV_WC_EX_WITH_COMPLETION_TIMESTAMP = 1 << 7, /* Require completion timestamp in WC /*
IBV_WC_EX_WITH_CVLAN = 1 << 8, /* Require VLAN info in WC */
IBV_WC_EX_WITH_FLOW_TAG = 1 << 9, /* Require flow tag in WC */
};
enum ibv_cq_init_attr_mask {
IBV_CQ_INIT_ATTR_MASK_FLAGS = 1 << 0,
};
enum ibv_create_cq_attr_flags {
IBV_CREATE_CQ_ATTR_SINGLE_THREADED = 1 << 0, /* This CQ is used from a single threaded, thus no locking is required */
};
Polling an extended CQ
In order to poll an extended CQ efficiently, a user could use the
following functions.
Completion iterator functions
int ibv_start_poll(struct ibv_cq_ex *cq, struct ibv_poll_cq_attr
*attr)
Start polling a batch of work completions. attr is given in
order to make this function easily extensible in the future.
This function either returns 0 on success or an error code
otherwise. When no completions are available on the CQ, ENOENT
is returned, but the CQ remains in a valid state. On success,
querying the completion's attribute could be done using the
query functions described below. If an error code is given,
end_poll shouldn't be called.
int ibv_next_poll(struct ibv_cq_ex *cq)
This function is called in order to get the next work
completion. It has to be called after start_poll and before
end_poll are called. This function either returns 0 on success
or an error code otherwise. When no completions are available on
the CQ, ENOENT is returned, but the CQ remains in a valid state.
On success, querying the completion's attribute could be done
using the query functions described below. If an error code is
given, end_poll should still be called, indicating this is the
end of the polled batch.
void ibv_end_poll(struct ibv_cq_ex *cq)
This function indicates the end of polling batch of work
completions. After calling this function, the user should start
a new batch by calling start_poll.
Polling fields in the completion
Below members and functions are used in order to poll the
current completion. The current completion is the completion
which the iterator points to (start_poll and next_poll advances
this iterator). Only fields that the user requested via wc_flags
in ibv_create_cq_ex could be queried. In addition, some fields
are only valid in certain opcodes and status codes.
uint64_t wr_id - Can be accessed directly from struct ibv_cq_ex.
enum ibv_wc_status - Can be accessed directly from struct
ibv_cq_ex.
enum ibv_wc_opcode ibv_wc_read_opcode(struct ibv_cq_ex *cq); Get
the opcode from the current completion.
uint32_t ibv_wc_read_vendor_err(struct ibv_cq_ex *cq); Get the
vendor error from the current completion.
uint32_t ibv_wc_read_byte_len(struct ibv_cq_ex *cq); Get the
vendor error from the current completion.
uint32_t ibv_wc_read_imm_data(struct ibv_cq_ex *cq); Get the
immediate data field from the current completion.
uint32_t ibv_wc_read_qp_num(struct ibv_cq_ex *cq); Get the QP
number field from the current completion.
uint32_t ibv_wc_read_src_qp(struct ibv_cq_ex *cq); Get the
source QP number field from the current completion.
int ibv_wc_read_wc_flags(struct ibv_cq_ex *cq); Get the QP flags
field from the current completion.
uint16_t ibv_wc_read_pkey_index(struct ibv_cq_ex *cq); Get the
pkey index field from the current completion.
uint32_t ibv_wc_read_slid(struct ibv_cq_ex *cq); Get the slid
field from the current completion.
uint8_t ibv_wc_read_sl(struct ibv_cq_ex *cq); Get the sl field
from the current completion.
uint8_t ibv_wc_read_dlid_path_bits(struct ibv_cq_ex *cq); Get
the dlid_path_bits field from the current completion.
uint64_t ibv_wc_read_completion_ts(struct ibv_cq_ex *cq); Get
the completion timestamp from the current completion.
uint16_t ibv_wc_read_cvlan(struct ibv_cq_ex *cq); Get the CVLAN
field from the current completion.
uint32_t ibv_wc_read_flow_tag(struct ibv_cq_ex *cq); Get flow
tag from the current completion.
RETURN VALUE
ibv_create_cq_ex() returns a pointer to the CQ, or NULL if the request
fails.
NOTES
ibv_create_cq_ex() may create a CQ with size greater than or equal to
the requested size. Check the cqe attribute in the returned CQ for the
actual size.
CQ should be destroyed with ibv_destroy_cq.
SEE ALSO
ibv_create_cq(3), ibv_destroy_cq(3), ibv_resize_cq(3),
ibv_req_notify_cq(3), ibv_ack_cq_events(3), ibv_create_qp(3)
AUTHORS
Matan Barak <matanb@mellanox.com>
libibverbs 2016-05-08 IBV_CREATE_CQ_EX(3)
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