Commit ed6788c5 authored by Gal Pressman's avatar Gal Pressman Committed by Jakub Kicinski
Browse files

selftests: drv-net: limit RPS test CPUs to supported range 



The _get_unused_cpus() function can return CPU numbers >= 16, which
exceeds RPS_MAX_CPUS in toeplitz.c. When this happens, the test fails
with a cryptic message:

  # Exception| Traceback (most recent call last):
  # Exception|   File "/tmp/cur/linux/tools/testing/selftests/net/lib/py/ksft.py", line 319, in ksft_run
  # Exception|     func(*args)
  # Exception|   File "/tmp/cur/linux/tools/testing/selftests/drivers/net/hw/toeplitz.py", line 189, in test
  # Exception|     with bkg(" ".join(rx_cmd), ksft_ready=True, exit_wait=True) as rx_proc:
  # Exception|          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  # Exception|   File "/tmp/cur/linux/tools/testing/selftests/net/lib/py/utils.py", line 124, in __init__
  # Exception|     super().__init__(comm, background=True,
  # Exception|   File "/tmp/cur/linux/tools/testing/selftests/net/lib/py/utils.py", line 77, in __init__
  # Exception|     raise Exception("Did not receive ready message")
  # Exception| Exception: Did not receive ready message

Rename _get_unused_cpus() to _get_unused_rps_cpus() and cap the CPU
search range to RPS_MAX_CPUS.

Reviewed-by: default avatarNimrod Oren <noren@nvidia.com>
Signed-off-by: default avatarGal Pressman <gal@nvidia.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260210093110.1935149-1-gal@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 10ec0fc0

tools/testing/selftests/drivers/net/hw/toeplitz.py

+10 −7
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ from lib.py import ksft_variants, KsftNamedVariant, KsftSkipEx, KsftFailEx 


# "define" for the ID of the Toeplitz hash function

ETH_RSS_HASH_TOP = 1

# Must match RPS_MAX_CPUS in toeplitz.c

RPS_MAX_CPUS = 16





def _check_rps_and_rfs_not_configured(cfg):
@@ -67,23 +69,24 @@ def _get_irq_cpus(cfg): 
    return cpus





def _get_unused_cpus(cfg, count=2):

def _get_unused_rps_cpus(cfg, count=2):

    """

    Get CPUs that are not used by Rx queues.

    Returns a list of at least 'count' CPU numbers.

    Get CPUs that are not used by Rx queues for RPS.

    Returns a list of at least 'count' CPU numbers within

    the RPS_MAX_CPUS supported range.

    """



    # Get CPUs used by Rx queues

    rx_cpus = set(_get_irq_cpus(cfg))



    # Get total number of CPUs

    num_cpus = os.cpu_count()

    # Get total number of CPUs, capped by RPS_MAX_CPUS

    num_cpus = min(os.cpu_count(), RPS_MAX_CPUS)



    # Find unused CPUs

    unused_cpus = [cpu for cpu in range(num_cpus) if cpu not in rx_cpus]



    if len(unused_cpus) < count:

        raise KsftSkipEx(f"Need at {count} CPUs not used by Rx queues, found {len(unused_cpus)}")

        raise KsftSkipEx(f"Need at least {count} CPUs in range 0..{num_cpus - 1} not used by Rx queues, found {len(unused_cpus)}")



    return unused_cpus[:count]
@@ -181,7 +184,7 @@ def test(cfg, proto_flag, ipver, grp): 
        ksft_pr(f"RSS using CPUs: {irq_cpus}")

    elif grp == "rps":

        # Get CPUs not used by Rx queues and configure them for RPS

        rps_cpus = _get_unused_cpus(cfg, count=2)

        rps_cpus = _get_unused_rps_cpus(cfg, count=2)

        rps_mask = _configure_rps(cfg, rps_cpus)

        defer(_configure_rps, cfg, [])

        rx_cmd += ["-r", rps_mask]