Re: [PATCH v3 net-next 09/10] selftests/tc-testing: test that taprio can only be attached as root

[Vladimir Oltean]

Hi Vinicius,

On Wed, Aug 02, 2023 at 04:29:55PM -0700, Vinicius Costa Gomes wrote:
> Vladimir Oltean <vladimir.oltean@xxxxxxx> writes:
> This test is somehow flaky (all others are fine), 1 in ~4 times, it fails.
> 
> Taking a look at the test I couldn't quickly find out the reason for the
> flakyness.
> 
> Here's the verbose output of one of the failures:
> 
> vcgomes@otc-cfl-clr-30 ~/src/net-next/tools/testing/selftests/tc-testing $ sudo ./tdc.py -e 39b4 -v
> All test results:
> 
> 1..1
> not ok 1 39b4 - Reject grafting taprio as child qdisc of software taprio
> 	Could not match regex pattern. Verify command output:
> parse error: Objects must consist of key:value pairs at line 1, column 334

Interesting. I'm not seeing this, and I re-ran it a few times. The error
message seems to come from jq, as if it's not able to parse something.

Sorry, I only have caveman debugging techniques. Could you remove the
pipe into jq and rerun a few times, see what it prints when it fails?

diff --git a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json
index de51408544e2..bb6be1f78e31 100644
--- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json
+++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json
@@ -148,8 +148,8 @@
         ],
         "cmdUnderTest": "$TC qdisc replace dev $ETH parent 8001:7 taprio num_tc 8 map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 200 sched-entry S ff 20000000 clockid CLOCK_TAI",
         "expExitCode": "2",
-        "verifyCmd": "$TC -j qdisc show dev $ETH root | jq '.[].options.base_time'",
-        "matchPattern": "0",
+        "verifyCmd": "$TC -j qdisc show dev $ETH root",
+        "matchPattern": "\\[{\"kind\":\"taprio\",\"handle\":\"8001:\",\"root\":true,\"refcnt\":9,\"options\":{\"tc\":0,\"map\":\\[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0\\],\"queues\":\\[\\],\"clockid\":\"TAI\",\"base_time\":0,\"cycle_time\":20000000,\"cycle_time_extension\":0,\"schedule\":\\[{\"index\":0,\"cmd\":\"S\",\"gatemask\":\"0xff\",\"interval\":20000000}\\],\"max-sdu\":\\[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0\\],\"fp\":\\[\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\",\"E\"\\]}}\\]",
         "matchCount": "1",
         "teardown": [
             "$TC qdisc del dev $ETH root",