mac80211: Dynamically set CoDel parameters per station
CoDel can be too aggressive if a station sends at a very low rate,
leading reduced throughput. This gets worse the more stations are
present, as each station gets more bursty the longer the round-robin
scheduling between stations takes.
This adds dynamic adjustment of CoDel parameters per station. It uses
the rate selection information to estimate throughput and sets more
lenient CoDel parameters if the estimated throughput is below a
threshold (modified by the number of active stations).
A new callback is added that drivers can use to notify mac80211 about
changes in expected throughput, so the same adjustment can be made for
cards that implement rate control in firmware. Drivers that don't use
this will just get the default parameters.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
[remove currently unnecessary EXPORT_SYMBOL, fix kernel-doc, remove
inline annotation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 76ed24a..e01daff 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -4205,6 +4205,22 @@
int max_rates);
/**
+ * ieee80211_sta_set_expected_throughput - set the expected tpt for a station
+ *
+ * Call this function to notify mac80211 about a change in expected throughput
+ * to a station. A driver for a device that does rate control in firmware can
+ * call this function when the expected throughput estimate towards a station
+ * changes. The information is used to tune the CoDel AQM applied to traffic
+ * going towards that station (which can otherwise be too aggressive and cause
+ * slow stations to starve).
+ *
+ * @pubsta: the station to set throughput for.
+ * @thr: the current expected throughput in kbps.
+ */
+void ieee80211_sta_set_expected_throughput(struct ieee80211_sta *pubsta,
+ u32 thr);
+
+/**
* ieee80211_tx_status - transmit status callback
*
* Call this function for all transmitted frames after they have been