net.core.dev_weight monitor

[daliang111]

is there any way to monitor the dev_weight， /proc/net/softnet_stat have no info about dev_weight.
like the kernel code, no way to monitor if dev_weight is to small?
void __qdisc_run(struct Qdisc q){
int quota = dev_tx_weight; // max send package num
int packets;
while (qdisc_restart(q, &packets)) {
/
* Ordered by possible occurrence: Postpone processing if
* 1. we've exceeded packet quota
* 2. another process needs the CPU; */
quota -= packets;
if (quota <= 0 || need_resched()) { //quota is <=0, next softirq and break
__netif_schedule(q);
break;
}
}
}

[zersh01]

dev_weight = net.core.netdev_budget

The structure of the /proc/net/softnet_stat file is typically as follows (as of the latest Linux kernel versions):
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

Each field is presented in hexadecimal format. Here's what these fields usually represent:

1. processed: The number of processed packets.
2. dropped: The number of packets that were dropped due to queue overflow.
3. time_squeeze: The number of times netdev_budget was exhausted (i.e., when the number of processed packets reached the limit set by net.core.netdev_budget).
4. cpu_collision: Collisions with other CPU processes.
5. received_rps: The number of packets processed in the context of RPS (Receive Packet Steering).
6. flow_limit_count: The number of times flow limit was exceeded.

The time_squeeze field is particularly important if you are interested in how often the netdev_budget is insufficient for processing all packets in the queue during one softirq call. If this value is high, it may indicate that the current net.core.netdev_budget is too low for the current load and should be increased to improve the performance of the network subsystem.

[leandromoreira]

https://github.com/leandromoreira/linux-network-performance-parameters?tab=readme-ov-file#interrupt-coalescing-soft-irq-and-ingress-qdisc

[daliang111]

what is different between net.core.netdev_budget and net.core.dev_weight，and is any way to moniotr if dev_weight is too small ？
time_squeeze is about net.core.netdev_budget ，nothing to do with net.core.dev_weight . kernel code,
https://elixir.bootlin.com/linux/v5.0/source/net/core/dev.c#L6389

budget=netdev_budget if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit))) { sd->time_squeeze++; break; }

and
net.core.netdev_budget(system parameter ) ---->netdev_budget(kernel code)
net.core.dev_weight * net.core.dev_weight_tx_bias ----> dev_tx_weight
net.core.dev_weight * net.core.dev_weight_rx_bias ----> dev_rx_weight

i want to monitor whether dev_weight is suitable，if dev_weight is too small ，which monitor metric can show it？