On Fri, Feb 2, 2024 at 12:21 PM Jakub Kicinski [off-list ref] wrote:

On Wed, 31 Jan 2024 10:54:33 +0800 Jason Xing wrote:

quoted

quoted

[danielj@sw-mtx-051 upstream]$ ethtool -S ens2f1np1 | grep 'stop\|wake'
     tx_queue_stopped: 0
     tx_queue_wake: 0
     tx0_stopped: 0
     tx0_wake: 0
     ....

Yes, that's it! What I know is that only mlx drivers have those two
counters, but they are very useful when debugging some issues or
tracking some historical changes if we want to.

Can you say more? I'm curious what's your use case.

I'm not working at Nvidia, so my point of view may differ from theirs.
From what I can tell is that those two counters help me narrow down
the range if I have to diagnose/debug some issues.
1) I sometimes notice that if some irq is held too long (say, one
simple case: output of printk printed to the console), those two
counters can reflect the issue.
2) Similarly in virtio net, recently I traced such counters the
current kernel does not have and it turned out that one of the output
queues in the backend behaves badly.
...

Stop/wake queue counters may not show directly the root cause of the
issue, but help us 'guess' to some extent.

Thanks,
Jason