cbq: incorrect processing of high limits
currently cbq works incorrectly for limits > 10% real link bandwidth,
and practically does not work for limits > 50% real link bandwidth.
Below are results of experiments taken on 1 Gbit link
In shaper | Actual Result
100M | 108 Mbps
200M | 244 Mbps
300M | 412 Mbps
500M | 893 Mbps
This happen because of q->now changes incorrectly in cbq_dequeue():
when it is called before real end of packet transmitting,
L2T is greater than real time delay, q_now gets an extra boost
but never compensate it.
To fix this problem we prevent change of q->now until its synchronization
with real time.
Signed-off-by: Vasily Averin <email@example.com>
Reviewed-by: Alexey Kuznetsov <firstname.lastname@example.org>
Acked-by: Eric Dumazet <email@example.com>
Signed-off-by: David S. Miller <firstname.lastname@example.org>
1 file changed