Commit c3572acf authored by Cong Wang's avatar Cong Wang Committed by Paolo Abeni
Browse files

selftests/tc-testing: Add an HFSC qlen accounting test 



This test reproduces a scenario where HFSC queue length and backlog accounting
can become inconsistent when a peek operation triggers a dequeue and possible
drop before the parent qdisc updates its counters. The test sets up a DRR root
qdisc with an HFSC class, netem, and blackhole children, and uses Scapy to
inject a packet. It helps to verify that HFSC correctly tracks qlen and backlog
even when packets are dropped during peek-induced dequeue.

Cc: Mingi Cho <mincho@theori.io>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250518222038.58538-3-xiyou.wangcong@gmail.com


Reviewed-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 3f981138

tools/testing/selftests/tc-testing/tc-tests/infra/qdiscs.json

+27 −0
Original line number Diff line number Diff line
@@ -573,5 +573,32 @@ 
        "teardown": [

            "$TC qdisc del dev $DEV1 handle 1: root"

        ]

    },

    {

        "id": "831d",

        "name": "Test HFSC qlen accounting with DRR/NETEM/BLACKHOLE chain",

        "category": ["qdisc", "hfsc", "drr", "netem", "blackhole"],

        "plugins": { "requires": ["nsPlugin", "scapyPlugin"] },

        "setup": [

            "$IP link set dev $DEV1 up || true",

            "$TC qdisc add dev $DEV1 root handle 1: drr",

            "$TC filter add dev $DEV1 parent 1: basic classid 1:1",

            "$TC class add dev $DEV1 parent 1: classid 1:1 drr",

            "$TC qdisc add dev $DEV1 parent 1:1 handle 2: hfsc def 1",

            "$TC class add dev $DEV1 parent 2: classid 2:1 hfsc rt m1 8 d 1 m2 0",

            "$TC qdisc add dev $DEV1 parent 2:1 handle 3: netem",

            "$TC qdisc add dev $DEV1 parent 3:1 handle 4: blackhole"

        ],

        "scapy": {

            "iface": "$DEV0",

            "count": 5,

            "packet": "Ether()/IP(dst='10.10.10.1', src='10.10.10.10')/ICMP()"

        },

        "cmdUnderTest": "$TC -s qdisc show dev $DEV1",

        "expExitCode": "0",

        "verifyCmd": "$TC -s qdisc show dev $DEV1",

        "matchPattern": "qdisc hfsc",

        "matchCount": "1",

        "teardown": ["$TC qdisc del dev $DEV1 root handle 1: drr"]

    }

]