On 2/21/2018 12:00 PM, Toke Høiland-Jørgensen wrote:
Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> writes:
On 2/19/2018 6:02 PM, Toke Høiland-Jørgensen wrote:
This series adds TXQ parameters and statistics that were previously only
available through debugfs to the nl80211 userspace interface and the
cfg80211 kernel interface. Patches for iw to print the statistics and
change the settings are included.
So what is your motivation for having this exposed through nl80211.
For the average end-user the stats and parameters are fairly fuzzy.
Two reasons, basically:
1. Visibility and statistics; this is basically the same information
that is available at the qdisc layer (with `tc -s qdisc`), but which
has been missing on WiFi interfaces ever sine we switched to the TXQ
structure. Having this available has been quite valuable for
debugging qdisc setups on wired links, and it's not always feasible
to ask users to recompile their kernels with debugfs enabled.
2. Having visibility into the queues from userspace makes it possible to
make decisions based upon (e.g.) which stations are currently
backlogged. I'm working on a "policy mode" for the airtime fairness
scheduler which will use this capability.
I see. Was just wondering whether there were concrete user-space
applications planned to use the information. Cool.
So can we expect some manual in which is described what parameter
should be tweaked based on the retrieved statistics.
Heh, not sure I'll promise a whole manual, but I am happy to write a
blog post (or wiki page if that's better) explaining what these values
mean and what insight one might gain from them.
My preference would be to have something on wireless.wiki.kernel.org.
Another option might be to add kerneldoc section for this.
Regards,
Arend
