Lower the expected level of traffic in the pp_alloc_fail test and calculate failure counter thresholds based on the traffic rather than using a fixed constant.

We only have "QEMU HW" in NIPA right now, and the test (due to debug dependencies) only works on debug kernels in the first place. We need some place for it to pass otherwise it seems to be bit rotting. So lower the traffic threshold so that it passes on QEMU and with a debug kernel...

Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org --- v2: - use seen_fails in 2 more places

CC: shuah@kernel.org CC: johndale@cisco.com CC: linux-kselftest@vger.kernel.org --- .../selftests/drivers/net/hw/pp_alloc_fail.py | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/pp_alloc_fail.py b/tools/testing/selftests/drivers/net/hw/pp_alloc_fail.py index fc66b7a7b149..2a51b60df8a1 100755 --- a/tools/testing/selftests/drivers/net/hw/pp_alloc_fail.py +++ b/tools/testing/selftests/drivers/net/hw/pp_alloc_fail.py @@ -7,6 +7,7 @@ Test driver resilience vs page pool allocation failures.

import errno import time +import math import os from lib.py import ksft_run, ksft_exit, ksft_pr from lib.py import KsftSkipEx, KsftFailEx @@ -62,7 +63,7 @@ from lib.py import cmd, tool, GenerateTraffic stat1 = get_stats() time.sleep(1) stat2 = get_stats() - if stat2['rx-packets'] - stat1['rx-packets'] < 15000: + if stat2['rx-packets'] - stat1['rx-packets'] < 4000: raise KsftFailEx("Traffic seems low:", stat2['rx-packets'] - stat1['rx-packets'])

@@ -89,11 +90,16 @@ from lib.py import cmd, tool, GenerateTraffic time.sleep(3) s2 = get_stats()

- if s2['rx-alloc-fail'] - s1['rx-alloc-fail'] < 1: + seen_fails = s2['rx-alloc-fail'] - s1['rx-alloc-fail'] + if seen_fails < 1: raise KsftSkipEx("Allocation failures not increasing") - if s2['rx-alloc-fail'] - s1['rx-alloc-fail'] < 100: - raise KsftSkipEx("Allocation increasing too slowly", s2['rx-alloc-fail'] - s1['rx-alloc-fail'], - "packets:", s2['rx-packets'] - s1['rx-packets']) + pkts = s2['rx-packets'] - s1['rx-packets'] + # Expecting one failure per 512 buffers, 3.1x safety margin + want_fails = math.floor(pkts / 512 / 3.1) + if seen_fails < want_fails: + raise KsftSkipEx("Allocation increasing too slowly", seen_fails, + "packets:", pkts) + ksft_pr(f"Seen: pkts:{pkts} fails:{seen_fails} (pass thrs:{want_fails})")

# Basic failures are fine, try to wobble some settings to catch extra failures check_traffic_flowing()