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NAME |SYNOPSIS |ARGUMENTS |DESCRIPTION |RETURN VALUE |NOTES |PORT SPACE |SEE ALSO |COLOPHON | |
RDMA_CREATE_ID(3) Librdmacm Programmer's ManualRDMA_CREATE_ID(3)rdma_create_id - Allocate a communication identifier.
#include <rdma/rdma_cma.h>int rdma_create_id (struct rdma_event_channel *channel, structrdma_cm_id **id, void *context, enum rdma_port_spaceps);
channel The communication channel that events associated with the allocated rdma_cm_id will be reported on. This may be NULL. id A reference where the allocated communication identifier will be returned. context User specified context associated with the rdma_cm_id. ps RDMA port space.
Creates an identifier that is used to track communication information.
Returns 0 on success, or -1 on error. If an error occurs, errno will be set to indicate the failure reason.
Rdma_cm_id's are conceptually equivalent to a socket for RDMA communication. The difference is that RDMA communication requires explicitly binding to a specified RDMA device before communication can occur, and most operations are asynchronous in nature. Asynchronous communication events on an rdma_cm_id are reported through the associated event channel. If the channel parameter is NULL, the rdma_cm_id will be placed into synchronous operation. While operating synchronously, calls that result in an event will block until the operation completes. The event will be returned to the user through the rdma_cm_id structure, and be available for access until another rdma_cm call is made. Users must release the rdma_cm_id by calling rdma_destroy_id.
Details of the services provided by the different port spaces are outlined below. RDMA_PS_TCP Provides reliable, connection-oriented QP communication. Unlike TCP, the RDMA port space provides message, not stream, based communication. RDMA_PS_UDP Provides unreliable, connectionless QP communication. Supports both datagram and multicast communication. RDMA_PS_IB Provides for any IB services (UD, UC, RC, XRC, etc.).
rdma_cm(7),rdma_create_event_channel(3),rdma_destroy_id(3),rdma_get_devices(3),rdma_bind_addr(3),rdma_resolve_addr(3),rdma_connect(3),rdma_listen(3),rdma_set_option(3)
This page is part of therdma-core (RDMA Core Userspace Libraries and Daemons) project. Information about the project can be found at ⟨https://github.com/linux-rdma/rdma-core⟩. If you have a bug report for this manual page, send it to linux-rdma@vger.kernel.org. This page was obtained from the project's upstream Git repository ⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2025-08-11. (At that time, the date of the most recent commit that was found in the repository was 2025-08-04.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which isnot part of the original manual page), send a mail to man-pages@man7.orglibrdmacm 2010-07-19RDMA_CREATE_ID(3)Pages that refer to this page:rdma_bind_addr(3), rdma_connect(3), rdma_dereg_mr(3), rdma_destroy_id(3), rdma_getaddrinfo(3), rdma_migrate_id(3), rdma_post_recv(3), rdma_post_recvv(3), rdma_reg_msgs(3), rdma_reg_read(3), rdma_reg_write(3), rdma_resolve_addr(3), rdma_set_option(3), rdma_cm(7)
HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. | |