[LARTC] HFSC traffic loss bug, kernel 2.6.16.24

[Patrick McHardy]

Leo Wetz wrote:
> Hello,
> 
> I have finally managed to understand HFSC up to a level which allowed me to
> create a QoS script which maintains low VoIP latency while running stuff
> like eMule.
> 
> Unfortunately, HFSC seems to have a severe bug.
> Why do I consider this as a bug defenitely?
> Well, my script runs without any errors, then QoS works perfectly for some
> hours, no error messages in kernel log.
> Then randomly the kernel starts saying this:
> 
> Sep 10 17:14:51 router kernel: HFSC: Non-work-conserving qdisc ?
> Sep 10 17:14:56 router kernel: printk: 266 messages suppressed.
> Sep 10 17:14:56 router kernel: HFSC: Non-work-conserving qdisc ?
> Sep 10 17:15:01 router kernel: printk: 259 messages suppressed.
> Sep 10 17:15:01 router kernel: HFSC: Non-work-conserving qdisc ?
> Sep 10 17:15:06 router kernel: printk: 294 messages suppressed.
> Sep 10 17:15:06 router kernel: HFSC: Non-work-conserving qdisc ?
> 
> It floods the whole kernel log with this.
> Traffic is also heavily affected by package loss when this happens, thus I
> cannot ignore it.
> I have to check my kernel log when I notice that I cannot access websites
> anymore and then restart QoS manually.
> 
> My complete QoS script is attached to this mail.
> If this is not the right location for the bug report please tell me whom I
> should contact.

This is not a bug. You can't attach non-work-conserving qdiscs to
HFSC (and it doesn't make any sense). Just use classes instead
of adding HTB qdiscs.