Messages in this thread | | | Date | Thu, 18 Jul 2013 13:03:35 -0700 (PDT) | Subject | Re: [PATCH BUGFIX] pkt_sched: sch_qfq: remove a source of high packet delay/jitter | From | David Miller <> |
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From: Paolo Valente <paolo.valente@unimore.it> Date: Tue, 16 Jul 2013 08:52:30 +0200
... > This patch addresses this issue by just using the above > 'instantaneous' value of the weight sum, instead of the maximum > possible value, when updating the system virtual time. After the > instantaneous weight sum is decreased, QFQ+ may deviate from the ideal > service for a time interval in the order of the time to serve one > maximum-size packet for each backlogged class. The worst-case extent > of the deviation exhibited by QFQ+ during this time interval [1] is > basically the same as of the deviation described above (but, without > this patch, QFQ+ suffers from such a deviation all the time). Finally, > this patch modifies the comment to the function qfq_slot_insert, to > make it coherent with the fact that the weight sum used by QFQ+ can > now be lower than the maximum possible value. > > [1] P. Valente, "Extending WF2Q+ to support a dynamic traffic mix", > Proceedings of AAA-IDEA'05, June 2005. > > Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Thank you for this amazing commit message.
Since you explained everything, even if I don't understand all of the details of QFQ/QFQ+ I can in fact be confident in your change.
Applied and queued up for -stable, thanks!
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