Re: [PATCH net-next] selftests: drv-net: toeplitz: cap the Rx queue count
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2026-06-30 17:11:17
Also in:
linux-kselftest
Jakub Kicinski wrote:
The RPS test needs a free CPU within the first RPS_MAX_CPUS (16) cores. This is easily violated if the NIC or env allocates the IRQs to cores linearly. Cap the Rx queues at 8, we don't need more. This makes the test pass on CX7 in NIPA. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
quoted hunk ↗ jump to hunk
--- CC: shuah@kernel.org CC: willemb@google.com CC: noren@nvidia.com CC: gal@nvidia.com CC: linux-kselftest@vger.kernel.org --- .../selftests/drivers/net/hw/toeplitz.py | 22 +++++++++++++++++++ 1 file changed, 22 insertions(+)diff --git a/tools/testing/selftests/drivers/net/hw/toeplitz.py b/tools/testing/selftests/drivers/net/hw/toeplitz.py index cd7e080e6f84..571732198b93 100755 --- a/tools/testing/selftests/drivers/net/hw/toeplitz.py +++ b/tools/testing/selftests/drivers/net/hw/toeplitz.py@@ -21,6 +21,8 @@ from lib.py import ksft_variants, KsftNamedVariant, KsftSkipEx, KsftFailEx ETH_RSS_HASH_TOP = 1 # Must match RPS_MAX_CPUS in toeplitz.c RPS_MAX_CPUS = 16 +# Cap Rx queues so IRQ pinning leaves free CPUs in the RPS_MAX_CPUS range +QUEUE_CAP = 8 def _check_rps_and_rfs_not_configured(cfg):@@ -48,6 +50,25 @@ RPS_MAX_CPUS = 16 return int(data) +def _cap_queue_count(cfg): + ehdr = {"header": {"dev-index": cfg.ifindex}} + chans = cfg.ethnl.channels_get(ehdr) + + config = {} + restore = {} + for key in ("combined-count", "rx-count"):
This assumes that combined and rx are not set at the same time. SGTM, not expected in real devices. But technically they could be.
quoted hunk ↗ jump to hunk
+ cur = chans.get(key, 0) + if cur > QUEUE_CAP: + config[key] = QUEUE_CAP + restore[key] = cur + + if not config: + return + + cfg.ethnl.channels_set(ehdr | config) + defer(cfg.ethnl.channels_set, ehdr | restore) + + def _get_irq_cpus(cfg): """ Read the list of IRQs for the device Rx queues.@@ -177,6 +198,7 @@ RPS_MAX_CPUS = 16 ] if grp: + _cap_queue_count(cfg) _check_rps_and_rfs_not_configured(cfg) if grp == "rss": irq_cpus = ",".join([str(x) for x in _get_irq_cpus(cfg)])-- 2.54.0