[Codel] [PATCH v12] codel: Controlled Delay AQM

[Dave Taht]

On Wed, May 9, 2012 at 8:54 AM, Eric Dumazet <eric.dumazet at gmail.com> wrote:
> On Wed, 2012-05-09 at 08:47 -0700, Dave Taht wrote:
>> Doing (or leveraging) the timestamp on actual ingress to the system,
>> rather than entrance to the exiting queue, more accurately will
>> compensate for overall system loading and the overhead of traversing
>> 3+ pages of function calls to get it from the
>> entrance point to the exit, and should result in 'tighter' results.
>
>
> Most qdiscs dont need this timestamp, so it would add overhead in fast
> path.
>
> Also, the delta between 'entering' qdisc layer and entering codel
> enqueue is almost a constant for a given qdisc/filter setup, and less
> than one us :
>
> If you really want to take it into account, replace 'target 5000us' by
> 'target 5001 us'

In the special case of routers and switches with codel on by default,
I think it would help. I can code it up....

>
>



-- 
Dave Täht
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