svn commit: r258328 - head/sys/net

[Julian Elischer]

On 11/19/13, 3:04 AM, Robert Watson wrote:
> On Mon, 18 Nov 2013, George V. Neville-Neil wrote:
>
>>  Allow ethernet drivers to pass in packets connected via the 
>> nextpkt pointer.
>>  Handling packets in this way allows drivers to amortize work 
>> during packet reception.
>>
>>  Submitted by:    Vijay Singh
>>  Sponsored by:    NetApp
>
> Currently, it is quite easy to make mistakes regarding individual 
> mbuf chains vs. lists of mbuf chains.  This leads me to wonder 
> whether a new type, perhaps simply constructed on the stack before 
> passing in, should be used for KPIs that accept lists of packets. E.g.,
>
>     /*
>      * This structure is almost always allocated on a caller stack, so
>      * cannot itself be queued without memory allocation in most cases.
>      */
>     struct mbuf_queue {
>         struct mbuf    *mq_head;
>     };
>
>
It's hard to believe that we don't have a structure around already 
that we can't use. With Luigi's comment, I wonder that there isn't an 
mbuf_list structure already we can just steal. it could almost be the 
current interface input queue structure.