ibv_create_comp_channel, ibv_destroy_comp_channel

Creates or destroys a completion event channel.

Syntax

#include <rdma/verbs.h>
struct ibv_comp_channel *ibv_create_comp_channel(struct ibv_context *context)
int ibv_destroy_comp_channel(struct ibv_comp_channel *channel)

Description

ibv_create_comp_channel() creates a completion event channel for the RDMA device context, context. A completion channel is a mechanism for the user to receive notifications when new Completion Queue Event (CQE) has been placed on a completion queue (CQ).

ibv_destroy_comp_channel() destroys the completion event channel, channel.

Notes:
  • A completion channel is an abstraction introduced by libibverbs that does not exist in the InfiniBand Architecture verbs specification. A completion channel is essentially file descriptor that is used to deliver completion notifications to a userspace process. When a completion event is generated for a completion queue (CQ), the event is delivered via the completion channel attached to that CQ. This might be useful to steer completion events to different threads by using multiple completion channels.
  • ibv_destroy_comp_channel() fails if any CQs are still associated with the completion event channel being destroyed.

Parameters

context struct ibv_context from ibv_open_device.

Return Value

ibv_create_comp_channel() returns a pointer to the created completion event channel, or NULL if the request fails.

ibv_destroy_comp_channel() returns 0 on success, or the value of errno on failure (which indicates the failure reason).

Parent topic: Event Management
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