Re: [PATCH 1/3] cfg80211: add channel utilization stats to the survey command

[Felix Fietkau <nbd@openwrt.org>]

On 2010-10-09 2:17 PM, Helmut Schaa wrote:
> Am Samstag 09 Oktober 2010 schrieb Felix Fietkau:
>> Using these, user space can calculate a relative channel utilization
>> with arbitrary intervals by regularly taking snapshots of the survey
>> results.
> 
> What if you've got multiple consumers, wouldn't that mess up the
> survey results?
> 
> I mean, for example mac80211 and/or hostapd might want to use the busy time
> statistics for the BSS load IE while a different userspace process might
> want to monitor the channel utilization in order to detect a worsening
> channel condition.
> 
> If the consumers happen to use the same interval and request the survey
> very soon after each other one consumer will get the values on a nice (close
> to the query interval) time base while the other one will get the values
> based on a very small interval (which might lower the value's
> representativeness).
Multiple consumers work just fine, since the survey results are relative
to the time the hardware started using the channel, not relative to the
last request. Maybe my description was a bit unclear on that part.

- Felix