The test generates 16 flows, and verifies that traffic is distributed across two queues via the NICs RSS indirection table. The likelihood of the flows skewing to a single queue is high, so we retry sending traffic up to 3 times. Alternatively, we could increase the number of generated flows. But debug kernels may struggle to ramp this many flows. During manual testing, the test passed for 10,000 consecutive runs. Signed-off-by: Dimitri Daskalakis Signed-off-by: Jakub Kicinski --- .../selftests/drivers/net/hw/rss_ctx.py | 29 +++++++++++++++---- 1 file changed, 23 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/drivers/net/hw/rss_ctx.py b/tools/testing/selftests/drivers/net/hw/rss_ctx.py index d7cb30306368..51f4e7bc3e5d 100755 --- a/tools/testing/selftests/drivers/net/hw/rss_ctx.py +++ b/tools/testing/selftests/drivers/net/hw/rss_ctx.py @@ -166,9 +166,17 @@ def test_rss_key_indir(cfg): ksft_eq(1, max(data['rss-indirection-table'])) # Check we only get traffic on the first 2 queues - cnts = _get_rx_cnts(cfg) - GenerateTraffic(cfg).wait_pkts_and_stop(20000) - cnts = _get_rx_cnts(cfg, prev=cnts) + + # Retry a few times in case the flows skew to a single queue. + attempts = 3 + for attempt in range(attempts): + cnts = _get_rx_cnts(cfg) + GenerateTraffic(cfg).wait_pkts_and_stop(20000) + cnts = _get_rx_cnts(cfg, prev=cnts) + if cnts[0] >= 5000 and cnts[1] >= 5000: + break + ksft_pr(f"Skewed queue distribution, attempt {attempt + 1}/{attempts}: " + str(cnts)) + # 2 queues, 20k packets, must be at least 5k per queue ksft_ge(cnts[0], 5000, "traffic on main context (1/2): " + str(cnts)) ksft_ge(cnts[1], 5000, "traffic on main context (2/2): " + str(cnts)) @@ -178,9 +186,18 @@ def test_rss_key_indir(cfg): # Restore, and check traffic gets spread again reset_indir.exec() - cnts = _get_rx_cnts(cfg) - GenerateTraffic(cfg).wait_pkts_and_stop(20000) - cnts = _get_rx_cnts(cfg, prev=cnts) + for attempt in range(attempts): + cnts = _get_rx_cnts(cfg) + GenerateTraffic(cfg).wait_pkts_and_stop(20000) + cnts = _get_rx_cnts(cfg, prev=cnts) + if qcnt > 4: + if sum(cnts[:2]) < sum(cnts[2:]): + break + else: + if cnts[2] >= 3500: + break + ksft_pr(f"Skewed queue distribution, attempt {attempt + 1}/{attempts}: " + str(cnts)) + if qcnt > 4: # First two queues get less traffic than all the rest ksft_lt(sum(cnts[:2]), sum(cnts[2:]), -- 2.52.0