GenerateTraffic was added to spin up long-running iperf3 load, mainly to drive high PPS background traffic. It was never meant to provide stable throughput numbers, and trying to repurpose it for measurement does not make sense.

Introduce Iperf3Runner to allow tests to split out server/client configuration, control start/stop, and collect JSON output for analysis. This makes it possible to measure bandwidth directly when validating egress shaping.

GenerateTraffic stays as the background load generator, reusing the common iperf3 helpers under the hood.

Signed-off-by: Carolina Jubran cjubran@nvidia.com Reviewed-by: Cosmin Ratiu cratiu@nvidia.com Reviewed-by: Nimrod Oren noren@nvidia.com --- .../drivers/net/hw/lib/py/__init__.py | 5 +- .../selftests/drivers/net/lib/py/__init__.py | 5 +- .../selftests/drivers/net/lib/py/load.py | 84 +++++++++++++++++-- 3 files changed, 82 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py b/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py index fb010a48a5a1..7563a49fca65 100644 --- a/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py +++ b/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py @@ -28,7 +28,7 @@ try: ksft_setup from net.lib.py import ksft_eq, ksft_ge, ksft_in, ksft_is, ksft_lt, \ ksft_ne, ksft_not_in, ksft_raises, ksft_true, ksft_gt, ksft_not_none - from drivers.net.lib.py import GenerateTraffic, Remote + from drivers.net.lib.py import GenerateTraffic, Remote, Iperf3Runner from drivers.net.lib.py import NetDrvEnv, NetDrvEpEnv

__all__ = ["NetNS", "NetNSEnter", "NetdevSimDev", @@ -44,7 +44,8 @@ try: "ksft_eq", "ksft_ge", "ksft_in", "ksft_is", "ksft_lt", "ksft_ne", "ksft_not_in", "ksft_raises", "ksft_true", "ksft_gt", "ksft_not_none", "ksft_not_none", - "NetDrvEnv", "NetDrvEpEnv", "GenerateTraffic", "Remote"] + "NetDrvEnv", "NetDrvEpEnv", "GenerateTraffic", "Remote", + "Iperf3Runner"] except ModuleNotFoundError as e: print("Failed importing `net` library from kernel sources") print(str(e)) diff --git a/tools/testing/selftests/drivers/net/lib/py/__init__.py b/tools/testing/selftests/drivers/net/lib/py/__init__.py index b0c6300150fb..65de853e8ac6 100644 --- a/tools/testing/selftests/drivers/net/lib/py/__init__.py +++ b/tools/testing/selftests/drivers/net/lib/py/__init__.py @@ -44,10 +44,11 @@ try: "ksft_not_none", "ksft_not_none"]

from .env import NetDrvEnv, NetDrvEpEnv - from .load import GenerateTraffic + from .load import GenerateTraffic, Iperf3Runner from .remote import Remote

- __all__ += ["NetDrvEnv", "NetDrvEpEnv", "GenerateTraffic", "Remote"] + __all__ += ["NetDrvEnv", "NetDrvEpEnv", "GenerateTraffic", "Remote", + "Iperf3Runner"] except ModuleNotFoundError as e: print("Failed importing `net` library from kernel sources") print(str(e)) diff --git a/tools/testing/selftests/drivers/net/lib/py/load.py b/tools/testing/selftests/drivers/net/lib/py/load.py index c4e808407cc4..cef661ded8ab 100644 --- a/tools/testing/selftests/drivers/net/lib/py/load.py +++ b/tools/testing/selftests/drivers/net/lib/py/load.py @@ -2,21 +2,89 @@

import re import time +import json

from lib.py import ksft_pr, cmd, ip, rand_port, wait_port_listen

-class GenerateTraffic: - def __init__(self, env, port=None): - env.require_cmd("iperf3", local=True, remote=True)

+class Iperf3Runner: + """ + Sets up and runs iperf3 traffic. + """ + def __init__(self, env, port=None, server_ip=None, client_ip=None): + env.require_cmd("iperf3", local=True, remote=True) self.env = env - self.port = rand_port() if port is None else port - self._iperf_server = cmd(f"iperf3 -s -1 -p {self.port}", background=True) + self.server_ip = server_ip + self.client_ip = client_ip + + def _build_server(self): + cmdline = f"iperf3 -s -1 -p {self.port}" + if self.server_ip: + cmdline += f" -B {self.server_ip}" + return cmdline + + def _build_client(self, streams, duration, reverse): + host = self.env.addr if self.server_ip is None else self.server_ip + cmdline = f"iperf3 -c {host} -p {self.port} -P {streams} -t {duration} -J" + if self.client_ip: + cmdline += f" -B {self.client_ip}" + if reverse: + cmdline += " --reverse" + return cmdline + + def start_server(self): + """ + Starts an iperf3 server with optional bind IP. + """ + cmdline = self._build_server() + proc = cmd(cmdline, background=True) wait_port_listen(self.port) time.sleep(0.1) - self._iperf_client = cmd(f"iperf3 -c {env.addr} -P 16 -p {self.port} -t 86400", - background=True, host=env.remote) + return proc + + def start_client(self, background=False, streams=1, duration=10, reverse=False): + """ + Starts the iperf3 client with the configured options. + """ + cmdline = self._build_client(streams, duration, reverse) + return cmd(cmdline, background=background, host=self.env.remote) + + def measure_bandwidth(self, reverse=False): + """ + Runs an iperf3 measurement and returns the average bandwidth (Gbps). + Discards the first and last few reporting intervals and uses only the + middle part of the run where throughput is typically stable. + """ + self.start_server() + result = self.start_client(duration=10, reverse=reverse) + + if result.ret != 0: + raise Exception("iperf3 failed to run successfully") + try: + out = json.loads(result.stdout) + except json.JSONDecodeError as exc: + raise Exception("Failed to parse iperf3 JSON output") from exc + + intervals = out.get("intervals", []) + samples = [i["sum"]["bits_per_second"] / 1e9 for i in intervals] + if len(samples) < 10: + raise Exception(f"iperf3 returned too few intervals: {len(samples)}") + # Discard potentially unstable first and last 3 seconds. + stable = samples[3:-3] + + avg = sum(stable) / len(stable) + + return avg + + +class GenerateTraffic: + def __init__(self, env, port=None): + self.env = env + self.runner = Iperf3Runner(env, port) + + self._iperf_server = self.runner.start_server() + self._iperf_client = self.runner.start_client(background=True, streams=16, duration=86400)

# Wait for traffic to ramp up if not self._wait_pkts(pps=1000): @@ -61,7 +129,7 @@ class GenerateTraffic: def _wait_client_stopped(self, sleep=0.005, timeout=5): end = time.monotonic() + timeout

- live_port_pattern = re.compile(fr":{self.port:04X} 0[^6] ") + live_port_pattern = re.compile(fr":{self.runner.port:04X} 0[^6] ")

while time.monotonic() < end: data = cmd("cat /proc/net/tcp*", host=self.env.remote).stdout

Commit 7c32f7a2d3db ("selftests: net: py: don't default to shell=True") changed the cmd() helper to avoid spawning a shell unless explicitly requested.

The devlink_rate_tc_bw test enables SR-IOV by writing to the sriov_numvfs sysfs attribute using redirection. Without shell=True the redirection is not interpreted and the VF device never appears, causing the test to fail.

Fix by explicitly passing shell=True in the two places that update sriov_numvfs.

Signed-off-by: Carolina Jubran cjubran@nvidia.com Reviewed-by: Cosmin Ratiu cratiu@nvidia.com Reviewed-by: Nimrod Oren noren@nvidia.com --- tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py b/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py index 16e5dda5bee1..df71936531cf 100755 --- a/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py +++ b/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py @@ -117,8 +117,8 @@ def setup_vf(cfg, set_tc_mapping=True): except Exception as exc: raise KsftSkipEx(f"Failed to enable switchdev mode on {cfg.pci}") from exc try: - cmd(f"echo 1 > /sys/class/net/{cfg.ifname}/device/sriov_numvfs") - defer(cmd, f"echo 0 > /sys/class/net/{cfg.ifname}/device/sriov_numvfs") + cmd(f"echo 1 > /sys/class/net/{cfg.ifname}/device/sriov_numvfs", shell=True) + defer(cmd, f"echo 0 > /sys/class/net/{cfg.ifname}/device/sriov_numvfs", shell=True) except Exception as exc: raise KsftSkipEx(f"Failed to enable SR-IOV on {cfg.ifname}") from exc

Currently, tolerance is computed against the TC’s expected percentage, making TC3 (20%) validation overly strict and TC4 (80%) overly loose.

Update BandwidthValidator to take a dict of shares and compute bounds relative to the overall total, so that all shares are validated consistently.

Signed-off-by: Carolina Jubran cjubran@nvidia.com Reviewed-by: Cosmin Ratiu cratiu@nvidia.com Reviewed-by: Nimrod Oren noren@nvidia.com --- .../drivers/net/hw/devlink_rate_tc_bw.py | 74 ++++++++----------- 1 file changed, 30 insertions(+), 44 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py b/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py index db24bfc51da4..4e4faa9275bb 100755 --- a/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py +++ b/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py @@ -69,39 +69,35 @@ from lib.py import Iperf3Runner

class BandwidthValidator: """ - Validates bandwidth totals and per-TC shares against expected values - with a tolerance. + Validates total bandwidth and individual shares with tolerance + relative to the overall total. """

- def __init__(self): + def __init__(self, shares): self.tolerance_percent = 12 - self.expected_total_gbps = 1.0 - self.total_min_expected = self.min_expected(self.expected_total_gbps) - self.total_max_expected = self.max_expected(self.expected_total_gbps) - self.tc_expected_percent = { - 3: 20.0, - 4: 80.0, - } + self.expected_total = sum(shares.values()) + self.bounds = {} + + for name, exp in shares.items(): + self.bounds[name] = (self.min_expected(exp), self.max_expected(exp))

def min_expected(self, value): """Calculates the minimum acceptable value based on tolerance.""" - return value - (value * self.tolerance_percent / 100) + return value - (self.expected_total * self.tolerance_percent / 100)

def max_expected(self, value): """Calculates the maximum acceptable value based on tolerance.""" - return value + (value * self.tolerance_percent / 100) - - def bound(self, expected, value): - """Returns True if value is within expected tolerance.""" - return self.min_expected(expected) <= value <= self.max_expected(expected) + return value + (self.expected_total * self.tolerance_percent / 100)

- def tc_bandwidth_bound(self, value, tc_ix): + def bound(self, values): """ - Returns True if the given bandwidth value is within tolerance - for the TC's expected bandwidth. + Return True if all given values fall within tolerance. """ - expected = self.tc_expected_percent[tc_ix] - return self.bound(expected, value) + for name, value in values.items(): + low, high = self.bounds[name] + if not low <= value <= high: + return False + return True

def setup_vf(cfg, set_tc_mapping=True): @@ -353,38 +349,26 @@ def verify_total_bandwidth(bw_data, validator): """ total = bw_data['total_bw']

- if validator.bound(validator.expected_total_gbps, total): + if validator.bound({"total": total}): return

- if total < validator.total_min_expected: + low, high = validator.bounds["total"] + + if total < low: raise KsftSkipEx( f"Total bandwidth {total:.2f} Gbps < minimum " - f"{validator.total_min_expected:.2f} Gbps; " - f"parent tx_max ({validator.expected_total_gbps:.1f} G) " + f"{low:.2f} Gbps; " + f"parent tx_max ({validator.expected_total:.1f} G) " f"not reached, cannot validate share" )

raise KsftFailEx( f"Total bandwidth {total:.2f} Gbps exceeds allowed ceiling " - f"{validator.total_max_expected:.2f} Gbps " - f"(VF tx_max set to {validator.expected_total_gbps:.1f} G)" + f"{high:.2f} Gbps " + f"(VF tx_max set to {validator.expected_total:.1f} G)" )

-def check_bandwidth_distribution(bw_data, validator): - """ - Checks whether the measured TC3 and TC4 bandwidth percentages - fall within their expected tolerance ranges. - - Returns: - bool: True if both TC3 and TC4 percentages are within bounds. - """ - tc3_valid = validator.tc_bandwidth_bound(bw_data['tc3_percentage'], 3) - tc4_valid = validator.tc_bandwidth_bound(bw_data['tc4_percentage'], 4) - - return tc3_valid and tc4_valid - - def run_bandwidth_distribution_test(cfg, set_tc_mapping): """ Runs parallel bandwidth measurements for both TCs and collects results. @@ -395,9 +379,10 @@ def run_bandwidth_distribution_test(cfg, set_tc_mapping): test_name = "with TC mapping" if set_tc_mapping else "without TC mapping" print_bandwidth_results(bw_data, test_name)

- verify_total_bandwidth(bw_data, cfg.bw_validator) + verify_total_bandwidth(bw_data, cfg.traffic_bw_validator)

- return check_bandwidth_distribution(bw_data, cfg.bw_validator) + return cfg.tc_bw_validator.bound({"tc3": bw_data['tc3_percentage'], + "tc4": bw_data['tc4_percentage']})

def test_no_tc_mapping_bandwidth(cfg): @@ -441,7 +426,8 @@ def main() -> None: if not cfg.pci: raise KsftSkipEx("Could not get PCI address of the interface")

- cfg.bw_validator = BandwidthValidator() + cfg.traffic_bw_validator = BandwidthValidator({"total": 1}) + cfg.tc_bw_validator = BandwidthValidator({"tc3": 20, "tc4": 80})

cases = [test_no_tc_mapping_bandwidth, test_tc_mapping_bandwidth]