dummynet dropping too many packets

[rihad]

Eugene Grosbein wrote:
> On Tue, Oct 06, 2009 at 08:28:35PM +0500, rihad wrote:
> 
>> I don't think net.inet.ip.intr_queue_maxlen is relevant to this problem, 
>> as net.inet.ip.intr_queue_drops is normally zero or very close to it at 
>> all times.
> 
> When net.isr.direct is 1, this queue is used very seldom.
> Would you change it to 0, it will be used extensively.
> 
Ah, ok, thanks. I'll try that tomorrow.

But still...

> Try setting net.isr.direct to 0 and make large net.inet.ip.intr_queue_maxlen.
> This way, one of your cores may run bce's thread, enqueue incoming
> packets and return to work immediately. The rest of processing may be
> performed by another kernel thread, hopefully using another core.
> Just to see if this changes anything. top -S should help here too.


It isn't the incoming bce0 losing packets, but rather the outgoing bce1, 
which is almost idle interrupt-wise:

   29 root          1 -68    -     0K    16K CPU1   1 223:39 55.86% 
irq256: bce0
   31 root          1 -68    -     0K    16K WAIT   2  19:27  4.10% 
irq257: bce1