On Sat, Jan 23, 2016 at 07:23:09AM -0800, Eric Dumazet wrote:
> On Fri, 2016-01-22 at 14:11 -0500, Jarod Wilson wrote:
>
> > ---
> > net/core/dev.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/net/core/dev.c b/net/core/dev.c
> > index 8cba3d8..1354c7b 100644
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -4153,8 +4153,11 @@ ncls:
> > else
> > ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
> > } else {
> > + if (deliver_exact)
> > + goto inactive; /* bond or team inactive slave */
> > drop:
> > atomic_long_inc(&skb->dev->rx_dropped);
> > +inactive:
> > kfree_skb(skb);
> > /* Jamal, now you will not able to escape explaining
> > * me how you were going to use this. :-)
>
> Note that if you still have a kfree_skb() instead of consume_skb(),
> some tools will still give you a wrong signal (packet dropped ...).
>
> But then maybe the signal is telling some truth.
>
> We receive a packet, and decide to drop it because no one was willing to
> handle it.
>
> Maybe someone wants to know a particular slave receives 10,000 such
> frames per second and hurts performance with useless work.
>
> We should at least increment some counter and maybe dump it with
> "ethtool -S" or something.
I've been digging into ethtool -S a little bit, and am somewhat at a loss
as to how I would wire into this. From what I've been able to figure out,
it's entirely device-specific-ish counters spit out. On my sfc cards, I
get rx_noskb_drops and rx_nodesc_drop_cnt output from ethtool -S, but for
the core network stack, these are actually added up and shoved into
rx_dropped, and no other network driver has those two individual counters.
By itself, rx_dropped isn't output directly anywhere from ethtool,
so far as I can see. And ethtool -S bondX shows absolutely nothing.
*Should* ethtool -S be dumping all the network core stats? I have to say I
was more than a little surprised at this:
# ethtool -S bond0
no stats available
Particularly given that if I look in /proc/net/dev or
/sys/devices/virtual/net/bond0/statistics/*, there are quite a few stats
that are being tracked and make their way out to userspace...
--
Jarod Wilson
ja...@redhat.com
