Making IFQ_MAXLEN tunable

[Maxim Sobolev]

Gary Jennejohn wrote:
> On Fri, 30 Apr 2010 13:23:13 -0700
> Maxim Sobolev <sobomax at sippysoft.com> wrote:
> 
>> Hi,
>>
>> Many network drivers in the FreeBSD kernel use the IFQ_MAXLEN value to 
>> set length of the outgoing packets queue. The default value for that 
>> parameter is only 50, which is pretty low especially for the cases when 
>> the system handles lot of small packets and can cause ENOBUFS in 
>> applications under the load. The following patch makes IFQ_MAXLEN a 
>> tunable. I am also tempted to bump the default value for IFQ_MAXLEN 
>> 10-fold, but would like to hear what do people think about it first.
>>
>> http://sobomax.sippysoft.com/IFQ_MAXLEN.diff
>>
> 
> Seems like a good idea, although I don't see where ifqmaxlen is being
> initialized.

sys/net/if.c

-Maxim