cmtime(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | NOTES | SEE ALSO | COLOPHON

CMTIME(1)                       librdmacm                      CMTIME(1)

NAME         top

       cmtime - RDMA CM connection steps timing test.

SYNOPSIS         top

       cmtime [-s server_address] [-b bind_address]
                      [-c connections] [-p port_number]
                      [-q base_qpn]
                      [-r retries] [-t timeout_ms]

DESCRIPTION         top

       Determines min, max, and average times for various "steps" in
       RDMA CM connection setup and teardown between a client and server
       application.

       "Steps" that are timed are: create ID, bind address, resolve
       address, resolve route, create QP, modify QP to INIT, modify QP
       to RTR, modify QP to RTS, CM connect, client establish,
       disconnect, destroy QP, and destroy ID.

       Many operations are asynchronous, allowing progress on multiple
       connections simultanesously.  The 'sum' output adds the time that
       all connections took for a given step.  The average 'us/conn' is
       the sum divided by the number of connections.  This is useful to
       identify steps which take a significant amount of time.  The min
       and max values are the smallest and largest times that any single
       connection took to complete a given step.

       The 'total' and 'avg/iter' times measure the time to complete a
       given step for all connections.  These two values take into
       account asynchronous operations.  For steps which are serial, the
       total and sum values will be roughly the same.  For asynchronous
       steps, the total may be significantly lower than the sum, as
       multiple connections will be in progress simultanesously.  The
       avg/iter is the total time divided by the number of connections.

       In many cases, times may not be available or only available on
       the client.  Is such situations, the output will show 0.

OPTIONS         top

       -s server_address
              The network name or IP address of the server system
              listening for connections.  The used name or address must
              route over an RDMA device.  This option must be specified
              by the client.

       -b bind_address
              The local network address to bind to.

       -c connections
              The number of connections to establish between the client
              and server.  (default 100)

       -p port_number
              The server's port number.

       -q base_qpn
              The first QP number to use when creating connections
              without allocating hardware QPs.  The test will use the
              values between base_qpn and base_qpn plus connections when
              connecting.  (default 1000)

       -n num_threads
              Sets the number of threads to spawn used to process
              connection events and hardware operations.  (default 1)

       -m mimic_qp_delay_us
              "Simulates" QP creation and modify calls by replacing them
              with a simple sleep function instead.  This allows testing
              the CM at larger scale than would be practical, or even
              possible given system configuration settings, if HW
              resources needed to be allocated.

       -r retries
              Number of retries when resolving address or route.
              (default 2)

       -S     Run connection rate test using sockets.  This provides a
              baseline comparison of RDMA connections versus TCP
              connections.  Sockets are set to blocking mode.

       -t timeout_ms
              Timeout in millseconds (ms) when resolving address or
              route.  (default 2000 - 2 seconds)

NOTES         top

       Basic usage is to start cmtime on a server system, then run
       cmtime -s server_name on a client system.

       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         top

       rdma_cm(7)

COLOPHON         top

       This page is part of the rdma-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
       [email protected].  This page was obtained from the
       project's upstream Git repository
       ⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2024-06-14.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2024-06-10.)  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 is not part of the original manual page), send a mail to
       [email protected]

librdmacm                      2017-04-28                      CMTIME(1)