On Tue, Jan 26, 2016 at 1:14 PM, Jarod Wilson <ja...@redhat.com> wrote:
> 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:
# ip -s -s link sh dev eth0
15: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc
pfifo_fast state DOWN mode DEFAULT group default qlen 1000
link/ether 3c:97:0e:be:91:7b brd ff:ff:ff:ff:ff:ff
RX: bytes packets errors dropped overrun mcast
0 0 0 0 0 0
RX errors: length crc frame fifo missed
0 0 0 0 0
TX: bytes packets errors dropped carrier collsns
0 0 0 0 0 0
TX errors: aborted fifo window heartbeat
0 0 0 0
So start with the following patch :
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index a30b78090594..7c762cf1e4d5 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -68,6 +68,8 @@ struct rtnl_link_stats64 {
/* for cslip etc */
__u64 rx_compressed;
__u64 tx_compressed;
+
+ __u64 rx_nohandler; /* packet was of no interest */
};
/* The struct should be in sync with struct ifmap */
