[dpdk-dev] DPDK-QoS- Using un-used bandwidth within a class

sreenaath vasudevan sreenaathkv at gmail.com
Mon Oct 24 09:04:47 CEST 2016


Hi
I am using DPDK QoS and I find something strange. I am not sure if
something is wrong with my config or my understanding of queue weights is
wrong.

In my config, I am using only 1 port and 1 subport and 1 pipe. Within that
pipe, I am using only the last class (C3). Port, subport and pipe are
configured with 100Mbps speed.
C3 is given the entire pipe's TB rate i.e entire bandwidth in essence.
In C3, I am giving relative weights of 1:4:2:2 for the four queues
q0,q1,q2,q3
When no other traffic is coming in to q0,q2,q3, I am pumping ~100Mbps in to
q1. However, I am seeing only 40% of the traffic going through q1. In other
words the max throughput allowed through the queue is based on its weight
and the unused bandwidth is not used.
Cannot the unused bandwidth from q0,q2 and q3 be used for q1?

Note-
Following is the QoS config output spit out by DPDK in syslog


SCHED: Low level config for pipe profile 0:

token bucket: period = 10, credits per period = 1, size = 25000

Traffic classes: period = 1250000, credits per period = [0, 0, 0, 125000]

Traffic class 3 oversubscription: weight = 0

WRR cost: [1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1], [4, 1, 2, 2]

SCHED: Low level config for subport 0:

Token bucket: period = 10, credits per period = 1, size = 25000

Traffic classes: period = 1250000, credits per period = [0, 0, 0, 125000]

Traffic class 3 oversubscription: wm min = 0, wm max = 0


-- 
regards
sreenaath


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