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mckey - Man Page

RDMA CM multicast setup and simple data transfer test.


mckey -m multicast_address [-s] [-b bind_address] [-c connections]
		[-C message_count] [-S message_size] [-p port_space]
mckey -m multicast_address -s [-b bind_address] [-c connections]
		[-C message_count] [-S message_size] [-p port_space]
mckey -M unmapped_multicast_address -b bind_address [-s] [-c connections]
		[-C message_count] [-S message_size] [-p port_space]


Establishes a set of RDMA multicast communication paths between nodes using the librdmacm, optionally transfers datagrams to receiving nodes, then tears down the communication.


-m multicast_address

IP multicast address to join.

-M unmapped_multicast_address

RDMA transport specific multicast address to join.


Send datagrams to the multicast group.

-b bind_address

The local network address to bind to.

-c connections

The number of QPs to join the multicast group.  (default 1)

-C message_count

The number of messages to transfer over each connection.  (default 10)

-S message_size

The size of each message transferred, in bytes.  This value must be smaller than the MTU of the underlying RDMA transport, or an error will occur. (default 100)


Join the multicast group as a send-only full-member. Otherwise the group is joined as a full-member.


Prevent multicast message loopback. Other receivers on the local system will not receive the multicast messages. Otherwise all multicast messages are also send to the host they originated from and local listeners (and probably the sending process itself) will receive the messages. -p port_space The port space of the datagram communication.  May be either the RDMA UDP (0x0111) or IPoIB (0x0002) port space.  (default RDMA_PS_UDP)


Basic usage is to start mckey -m multicast_address on a server system, then run mckey -m multicast_address -s on a client system.

Unique Infiniband SA assigned multicast GIDs can be retrieved by invoking mckey with a zero MGID or IP address.  (Example, -M 0 or -m  The assigned address will be displayed to allow mckey clients to join the created group.

Because this test maps RDMA resources to userspace, users must ensure that they have available system resources and permissions.  See the libibverbs README file for additional details.

See Also

rdma_cm(7), ucmatose(1), udaddy(1), rping(1)

Referenced By

rdma_client(1), rdma_cm(7), rdma_server(1), rdma_xclient(1), rdma_xserver(1), rping(1), ucmatose(1), udaddy(1).

2007-05-15 librdmacm