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Date: Fri, 29 Nov 2013 14:39:51 -0800
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Subject: Re: ip_output()/if_output() behaviour
From: Adrian Chadd <adrian@freebsd.org>
To: Julian Elischer <julian@freebsd.org>
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Cc: Michael Tuexen <Michael.Tuexen@lurchi.franken.de>,
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+1


On 29 November 2013 08:14, Julian Elischer <julian@freebsd.org> wrote:

>> ifnet(9) says:
>>
>>             if_transmit()
>>             Transmit a packet on an interface or queue it if the interface
>> is
>>             in use.  This function will return ENOBUFS if the devices
>> software
>>             and hardware queues are both full.  ...
>>
>> So I guess returning ENOBUFS when the packet was queued is wrong...
>
> I think it is.
>
> ENOBUFS means "I couldn't proceed due to no buffers"
> not "I used up the last one on this operation".

Yes, it's wrong. ENOBUFS means "couldn't queue; no buffers." Please
provide a diff against igb and I'll make sure Jack/Intel get it into
(his, freebsd) tree.

Thanks!



-adrian