From: Oliver Hartkopp <socketcan@hartkopp.net>
To: Jeroen Hofstee <jhofstee@victronenergy.com>,
"linux-can@vger.kernel.org" <linux-can@vger.kernel.org>
Subject: Re: rx-dropped increases if the can module is not loaded (yet)
Date: Wed, 2 Dec 2020 17:24:14 +0100 [thread overview]
Message-ID: <8a05136d-5582-c8ef-012c-fc6a25ba744b@hartkopp.net> (raw)
In-Reply-To: <dea3d0e6-9e75-671c-b318-830b080ce5d5@victronenergy.com>
On 02.12.20 16:47, Jeroen Hofstee wrote:
> Hello Oliver,
>
> On 11/28/20 6:44 PM, Oliver Hartkopp wrote:
>> On 27.11.20 17:09, Jeroen Hofstee wrote:
>>
>>> Since it took me a while to figure it out, it might be worthwhile to
>>> share.
>>> If a CAN-bus network interface is first set to up and only later used,
>>> the messages received in the meantime are counted by [1] as dropped.
>>
>> Interesting! But makes sense and is consistent: When the CAN frame is
>> not processed by the network layer is is just dropped in the rx path.
>>
>>> If the the can module is modprobed before the interface is upped, this
>>> is no longer the case.
>>>
>>> Perhaps it saves someone some time.
>>
>> So far we have not documented these details for the existing netdev
>> statistics. Do you think this is needed when the behaviour, which
>> leads to rx-dropped, is common for other netdevs also?
>>
>>
>
> Don't know... Perhaps we should simply wait and see how many
> people show up wondering where the rx-dropped frames are
> coming from?
>
ACK ;-)
Regards,
Oliver
prev parent reply other threads:[~2020-12-02 16:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-27 16:09 rx-dropped increases if the can module is not loaded (yet) Jeroen Hofstee
2020-11-28 17:44 ` Oliver Hartkopp
2020-12-02 15:47 ` Jeroen Hofstee
2020-12-02 16:24 ` Oliver Hartkopp [this message]
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