[Bloat] tc -s qdisc questions

Kevin Darbyshire-Bryant kevin at darbyshire-bryant.me.uk
Thu May 14 18:22:12 EDT 2015


Hi Chaps,

Further to Dave's recent request for 'tc -s qdisc' stats looking at 
drops vs ecn marks, please could someone take a look at these and 
explain to this idiot quite what is going on?  This is a particularly 
slow & ratty ADSL line providing my parents internet 'service'.  Before 
I got hold of it with OpenWrt CC trunk + cake jammed in it, 6 seconds of 
bufferbloat was not uncommon.  I'm using the default sqm scripts that 
arrive with the 'ceropackages' repo (used as a source of patched 
iproute2, cake, etc)  In essence 2 questions: 1) Why no ECN marks, only 
drops?  2) What falls into diffserv class 0 (alias, why has nothing used 
it?)

Your time, patience etc is greatly appreciated.

Kevin

root at Router:~# tc -s qdisc show dev pppoa-wan
qdisc cake 803a: root refcnt 2 bandwidth 256Kbit diffserv4 flows
  Sent 1928303 bytes 12121 pkt (dropped 73, overlimits 6915 requeues 0)
  backlog 0b 0p requeues 0
            Class 0     Class 1     Class 2     Class 3
   rate       256Kbit     240Kbit     192Kbit      64Kbit
   target      70.5ms      75.2ms      94.0ms     282.0ms
interval     564.0ms     601.6ms     752.0ms        2.3s
Pk delay         0us      91.4ms      17.5ms       3.2ms
Av delay         0us       2.9ms       2.9ms        53us
Sp delay         0us         5us       136us         7us
   pkts             0       11754         408          32
way inds           0           0           0           0
way miss           0         347         404           5
way cols           0           0           0           0
   bytes            0     1973100       28163        6537
   drops            0          73           0           0
   marks            0           0           0           0
qdisc ingress ffff: parent ffff:fff1 ----------------
  Sent 8221609 bytes 11969 pkt (dropped 6, overlimits 0 requeues 0)
  backlog 0b 0p requeues 0
root at Router:~# tc -s qdisc show dev ifb4pppoa-wan
qdisc cake 803b: root refcnt 2 bandwidth 1512Kbit besteffort flows
  Sent 7597496 bytes 11494 pkt (dropped 482, overlimits 10487 requeues 0)
  backlog 0b 0p requeues 0
            Class 0
   rate      1512Kbit
   target      12.0ms
interval     112.0ms
Pk delay       3.3ms
Av delay       289us
Sp delay         5us
   pkts         11976
way inds           0
way miss         769
way cols           0
   bytes      8270163
   drops          482
   marks            0

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/bloat/attachments/20150514/18e411e6/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4791 bytes
Desc: S/MIME Cryptographic Signature
URL: <https://lists.bufferbloat.net/pipermail/bloat/attachments/20150514/18e411e6/attachment-0002.bin>


More information about the Bloat mailing list