dummynet dropping too many packets

[rihad]

rihad wrote:
> Peter Jeremy wrote:
> 
>> Since the problem only appears to manifest when table(0) exceeds 2000
>> entries, have you considered splitting (at least temporarily) that
>> table (and possibly table(2)) into two (eg table(0) and table(4))?
>> This would help rule out an (unlikely) problem with table sizes.
> It was quite easy to simulate without touching any code:
> # ipfw table 0 list|wc -l
>     3697
> # move half the table into the new table(1)
> # ipfw table 0 list|head -n1800|while read ip pipeid; do ipfw -q table 1 
> add $ip $pipeid && ipfw -q table 0 delete $ip; done
> # ipfw table 0 list|wc -l
>     1899
> # ipfw table 1 list|wc -l
>     1800
> # ipfw add 1061 pipe tablearg ip from any to table'(1)' out recv bce0 
> xmit bce1
> 
> now the ipfw looks like this:
> 01060 pipe tablearg ip from any to table(0) out recv bce0 xmit bce1
> 01061 pipe tablearg ip from any to table(1) out recv bce0 xmit bce1
> 
> The drops are at 100-200 per second. It may have descreased by 100-200 
> drops.  Strangely, deleting rule 1061 instantly increases the drop rate 
> to 300-400 up to 700/s, although there's still only 1980 entries in 
> table(0), which is somewhat inexplicable.
> 
Splitting the table 0 across 4 tables in the same way, resulting in each 
having around 500-600 entries didn't help much either:
01060 pipe tablearg ip from any to table(0) out recv bce0 xmit bce1
01061 pipe tablearg ip from any to table(10) out recv bce0 xmit bce1
01061 pipe tablearg ip from any to table(11) out recv bce0 xmit bce1
01061 pipe tablearg ip from any to table(12) out recv bce0 xmit bce1


Still 100-200-300-400 drops/s.