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. Fixes: 9cf9aa77a1f6 ("selftests: drv-net: hw: convert the Toeplitz test to Python") Reviewed-by: Nimrod Oren Signed-off-by: Gal Pressman --- .../selftests/drivers/net/hw/toeplitz.py | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/drivers/net/hw/toeplitz.py b/tools/testing/selftests/drivers/net/hw/toeplitz.py index d288c57894f6..cd7e080e6f84 100755 --- a/tools/testing/selftests/drivers/net/hw/toeplitz.py +++ b/tools/testing/selftests/drivers/net/hw/toeplitz.py @@ -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] -- 2.52.0