12. gc-iputraffictest

This tool tests the data transfer between IPUs.

To use it to test data transfer between device 2 and device 3, for example, run:

gc-iputraffictest --device0 2 --device1 3 -j

The device numbers used are those returned by the gc-info tool.

The output will be plain text if the -j option is not specified. The JSON output will look something like this:

{
  "tile_to_tile": {
      "boards": {
          "0024.xxxx.8203321": {
              "power_sensors": {
                  "XDPE132G5C:0": "25.5",
                  "XDPE132G5C:1": "21"
              },
              "device_ids": [
                  "3",
                  "2"
              ],
              "type": "M2000",
              "board_power": "46.5"
          }
      },
      "device0": "2",
      "device1": "3",
      "duration_sec": "0.079266418000000005",
      "kbytes_transferred": "4096000",
      "gbytes_transferred": "3.90625",
      "gbps": "423.31207649625344",
      "errors": "0",
      "power": "46.5"
  }
}

The reported bandwidth is the simultaneous bi-directional bandwidth: the sum of the bandwidth from device0 to device1 and the bandwidth from device1 to device0.

If an error occurs during the test, then gc-iputraffictest will return a non-zero exit code, and output an error message.

You can use this tool to run a “soak test” of all the IPU-to-IPU links by running:

$ gc-iputraffictest --all-links

There is also a --forever option that will run either a point-to-point or all-link soak forever (until interrupted by Ctrl-C). The -j option is not available when --forever is used.

Note

The --device0 and --device1 arguments must be IDs for single IPUs, not groups of IPUs. (The test will connect to the smallest group containing both the sender and receiver.)

12.1. Usage

12.1.1. Allowed options

`-j, --json-output`	Emit JSON output
`--device0 {arg}`	First IPU of exchange
`--device1 {arg}`	Second IPU of exchange
`-i {arg}, --iterations {arg}`	Number of (64)KB transfers per tile (default: 1000)
`-v, --verbose`	Verbose output
`--superverbose`	Even more verbose output
`--amp`	Run high power consumption AMP loop on idle tiles
`--sync-before-amp`	AMP loop tiles sync with host before starting
`--pulseamp`	[=arg(=300)] ‘–amp’ option but with a delay between iterations.Interval specified in units of 1000 cycles
`--ipum-loopback`	Test using IPU-M loopback config
`--all-links`	[=arg(=0)] Exercise every link of a multi-ipu device at once. Defaults to the largest multi-ipu device in the system.
`--min-bandwidth {arg}`	Minimum bandwidth (Gbps) expected - fails if not reached
`--max-errcount {arg}`	Maximum error count expected - fails if exceeded
`--dump-tile-overview`	Dump tile overview upon failure
`--forever`	Transmit data forever
`-h, --help`	Produce help message
`--version`	Version number

12.1.2. Single ipu mode options

`--single-ipu-mode {arg}`	Run in single IPU mode. Required: run-master \| setup \| check
`-d {arg}, --device-id {arg}`	Single IPU mode device id
`--num-ipus {arg}`	Number of IPUs in larger device
`--dnc {arg}`	DNC id

12.1.3. Single ipu loopback mode

--single-ipu-loopback

Single IPU loopback mode. Requires device id.

Search help