rdma_destroy_event_channel man page
rdma_destroy_event_channel — Close an event communication channel.
void rdma_destroy_event_channel (struct rdma_event_channel *channel);
The communication channel to destroy.
Release all resources associated with an event channel and closes the associated file descriptor.
All rdma_cm_id's associated with the event channel must be destroyed, and all returned events must be acked before calling this function.
rdma_create_event_channel(3), rdma_get_cm_event(3), rdma_ack_cm_event(3)