Messages in this thread | | | Date | Mon, 21 May 2007 22:46:06 +0200 | From | Ingo Molnar <> | Subject | Re: bad networking related lag in v2.6.22-rc2 |
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* Anant Nitya <kernel@prachanda.info> wrote:
> I am posting links to the information you asked for. One more thing, > after digging a bit more I found its QoS shaping that is making the > box crawl. Once I disabled the traffic shaping everything comes back > to smooth and normal. Shaping being done on very low speed residential > ADSL 256/64 Kbps connection. If you want me to post shaping rules, > please free to ask. BTW its a simple HTB/SFQ rules. [...] > http://cybertek.info/taitai/trace-to-ingo.txt.bz2
thanks! This trace indeed includes the smoking gun, htb_dequeue() and __qdisc_run():
privoxy-12926 1.Ns1 1597us : rb_first (htb_dequeue)
this goes on, non-preemptible, for 160 milliseconds (!):
privoxy-12926 1.Ns1 161568us : rb_first (htb_dequeue) privoxy-12926 1.Ns1 161568us : qdisc_watchdog_schedule (htb_dequeue)
and finally manages to escape the loop:
privoxy-12926 1.Ns1 161597us : rb_first (htb_dequeue) privoxy-12926 1.Ns1 161597us : rb_first (htb_dequeue) privoxy-12926 1.Ns1 161599us : htb_safe_rb_erase (htb_dequeue) privoxy-12926 1.Ns1 161599us : rb_erase (htb_safe_rb_erase) privoxy-12926 1.Ns1 161600us : htb_change_class_mode (htb_dequeue) privoxy-12926 1.Ns1 161601us : htb_activate_prios (htb_change_class_mode)
and the system recovers.
David, any ideas about what's wrong with htb_dequeue(), based on this trace?
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