Enabling Byte Queue Limits in the ath5k wireless driver

Anirudh Sivaraman sk.anirudh at gmail.com
Sun Oct 6 09:31:57 EDT 2013


On Sat, Oct 5, 2013 at 11:39 PM, Simon Barber <simon at superduper.net> wrote:
> BQL does make sense, but TQL would be even better - 'Time Queue Limits'.
> Which would work based on an estimate of how much time each packet will take
> to send, and limiting the hardware queue to contain a total mount of 'time'.
> The purpose of the hardware queue is to mask interrupt and other latencies
> involved in refilling an empty queue - a time based phenomenon. Hence time
> is the best metric to control it - with fixed speed interfaced like ethernet
> bytes=time, but not so on wireless.
>

Thank you for your reply. TQL does make more sense for wireless at
least. However, assuming that someone implement a qdisc like CoDel and
attaches it to the wireless interface, doesn't TQL (or for that matter
BQL) lead to two possibly competing control loops (one at the qdisc,
and one at the device driver)?

Anirudh
> Simon
>
>
> On 10/3/2013 11:49 AM, Anirudh Sivaraman wrote:
>>
>> Hi,
>>
>> I am looking into enabling BQL for the ath5k driver, and was wondering
>> if anyone here knows of any prior efforts in this direction. In
>> particular, is BQL even a sensible strategy for wireless drivers?
>> Thank you in advance for any advice you may have in this regard.
>>
>> Anirudh
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>
>
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