From 665338b2a7a0139337d1f85be65ed16e487f84c1 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Mon, 7 Aug 2023 22:33:18 +0300 Subject: net/sched: taprio: dump class stats for the actual q->qdiscs[] This makes a difference for the software scheduling mode, where dev_queue->qdisc_sleeping is the same as the taprio root Qdisc itself, but when we're talking about what Qdisc and stats get reported for a traffic class, the root taprio isn't what comes to mind, but q->qdiscs[] is. To understand the difference, I've attempted to send 100 packets in software mode through class 8001:5, and recorded the stats before and after the change. Here is before: $ tc -s class show dev eth0 class taprio 8001:1 root leaf 8001: Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:2 root leaf 8001: Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:3 root leaf 8001: Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:4 root leaf 8001: Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:5 root leaf 8001: Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:6 root leaf 8001: Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:7 root leaf 8001: Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:8 root leaf 8001: Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 and here is after: class taprio 8001:1 root Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:2 root Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:3 root Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:4 root Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:5 root Sent 9400 bytes 100 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:6 root Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:7 root Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 class taprio 8001:8 root leaf 800d: Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0 window_drops 0 The most glaring (and expected) difference is that before, all class stats reported the global stats, whereas now, they really report just the counters for that traffic class. Finally, Pedro Tammela points out that there is a tc selftest which checks specifically which handle do the child Qdiscs corresponding to each class have. That's changing here - taprio no longer reports tcm->tcm_info as the same handle "1:" as itself (the root Qdisc), but 0 (the handle of the default pfifo child Qdiscs). Since iproute2 does not print a child Qdisc handle of 0, adjust the test's expected output. Link: https://lore.kernel.org/netdev/3b83fcf6-a5e8-26fb-8c8a-ec34ec4c3342@mojatatu.com/ Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20230807193324.4128292-6-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski --- tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools') 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 08d4861c2e78..860b55df0d6d 100644 --- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json +++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/taprio.json @@ -104,7 +104,7 @@ "cmdUnderTest": "$TC qdisc add dev $ETH root handle 1: taprio num_tc 3 map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 queues 1@0 1@0 1@0 base-time 1000000000 sched-entry S 01 300000 flags 0x1 clockid CLOCK_TAI", "expExitCode": "0", "verifyCmd": "$TC class show dev $ETH", - "matchPattern": "class taprio 1:[0-9]+ root leaf 1:", + "matchPattern": "class taprio 1:[0-9]+ root", "matchCount": "8", "teardown": [ "echo \"1\" > /sys/bus/netdevsim/del_device" -- cgit v1.2.3-58-ga151