xdp-project-bpf-examples/tc-policy/monitor_txq_usage.bt

#!/usr/bin/bpftrace

//BEGIN {
//	printf("Monitor TXQ usage\n");
//	printf(" - Remember: BPF set queue_mapping is one-less here (zero-indexed)\n");
//}

tracepoint:net:net_dev_start_xmit {
	$qm = args->queue_mapping;
	$dev = str(args->name, 16);

	@stat_txq_usage[$dev] = lhist($qm, 0,32,1);
}

/* Periodically print stats */
interval:s:3
{
	printf("\nPeriodic show stats - time: ");
        time();
	print(@stat_txq_usage);
}

/* Default bpftrace will print all remaining maps at END */
//END {
//	printf("END stats:\n");
//}