Re: [RFC PATCHv3 1/2] mac80211: Determine dynamic PS timeout based on ps-qos network latency

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2010-04-20 at 08:08 +0300, Juuso Oikarinen wrote:
> On Mon, 2010-04-19 at 16:42 +0200, ext Johannes Berg wrote:
> > On Fri, 2010-04-16 at 12:14 +0300, Juuso Oikarinen wrote:
> > > Determine the dynamic PS timeout based on the configured ps-qos network
> > > latency. For backwards wext compatibility, allow the dynamic PS timeout
> > > configured by the cfg80211 to overrule the automatically determined value.
> > 
> > This seems OK, but I fear that you'll write applications setting the
> > pm_qos network latency just to affect this parameter?
> > 
> 
> Well you have to see where I'm coming from - I must come up with a way
> to tune the dynamic ps timeout value from user-space in a way that is
> agreeable with others, and that is somewhat future-proof.

Well I personally think that's your first mistake ;)

Why does userspace care about the dynamic PS timeout value to start
with? All it should care about is the latency with which it can react to
network packets, no?

> That said, obviously the network latency should be tuned as, well, the
> expected network latency. In this phase though, there are no other
> parameters affected by the network latency, so the result is quite
> obvious - your fear will realise itself ;)

But there are, like the max sleep period in # of beacons.

johannes