Messages in this thread | | | Date | Thu, 15 May 2008 20:14:39 +0200 | From | Patrick McHardy <> | Subject | Re: NET_SCHED cbq dropping too many packets on a bonding interface |
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Jarek Poplawski wrote: > On Thu, May 15, 2008 at 06:09:36PM +0200, Patrick McHardy wrote: >> Kingsley Foreman wrote: >>> i just rolled back the kernel to 2.6.24 and im seeing the same thing, >>> >>> I was using 2.6.22 before and didn't see the problem, txqueuelen on the >>> bond0 interface is 0 (the default) >> That might explain things, although it shouldn't have worked before >> either. >> >> CBQ creates default pfifo qdiscs for its leaves, these use a limit >> of txqueuelen or 1 if it is zero. So even small bursts will cause >> drops. Do things improve if you set txqueuelen to a larger value >> *before* configuring the qdiscs? > > Kingsley wrote to me that even after changing txqueuelen to 1000 the > "dropped" number didn't change much. A debugging patch with printks > around all "sch->qstats.dropps++" showed only the end of cbq_enqueue().
Thats where packets dropped by default pfifo would be accounted. Did you change txqueuelen before or after setting up the qdiscs?
> I've asked to check tomorrow "pfifo limit 1000" for these drops too.
That will clear it up.
>> Another thing is that CBQ on bond will probably not work properly >> at all, it needs a real device since it measures the timing between >> dequeue events for idle time estimation. On software devices this >> doesn't work. > > Right, but these drops without any sign of overactions or overlimits > seem to show it's not about shaping (or it's not counted/documented > enough).
Yes, these drops are probably unrelated, just thought I mention it.
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