From ad38bfc916da6aee9160bfa5335aed8d6c190e39 Mon Sep 17 00:00:00 2001 From: Matti Gottlieb Date: Mon, 18 Nov 2013 19:06:45 +0200 Subject: mac80211: Tx frame latency statistics Measure TX latency and jitter statistics per station per TID. These Measurements are disabled by default and can be enabled via debugfs. Features included for each station's TID: 1. Keep count of the maximum and average latency of Tx frames. 2. Keep track of many frames arrived in a specific time range (need to enable through debugfs and configure the bins ranges) Signed-off-by: Matti Gottlieb Signed-off-by: Johannes Berg --- net/mac80211/tx.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'net/mac80211/tx.c') diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index e541856b4007..6d59e21cdb9f 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -1741,6 +1742,26 @@ fail: return NETDEV_TX_OK; /* meaning, we dealt with the skb */ } +/* + * Measure Tx frame arrival time for Tx latency statistics calculation + * A single Tx frame latency should be measured from when it is entering the + * Kernel until we receive Tx complete confirmation indication and the skb is + * freed. + */ +static void ieee80211_tx_latency_start_msrmnt(struct ieee80211_local *local, + struct sk_buff *skb) +{ + struct timespec skb_arv; + struct ieee80211_tx_latency_bin_ranges *tx_latency; + + tx_latency = rcu_dereference(local->tx_latency); + if (!tx_latency) + return; + + ktime_get_ts(&skb_arv); + skb->tstamp = ktime_set(skb_arv.tv_sec, skb_arv.tv_nsec); +} + /** * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type * subinterfaces (wlan#, WDS, and VLAN interfaces) @@ -1791,6 +1812,9 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb, rcu_read_lock(); + /* Measure frame arrival for Tx latency statistics calculation */ + ieee80211_tx_latency_start_msrmnt(local, skb); + switch (sdata->vif.type) { case NL80211_IFTYPE_AP_VLAN: sta = rcu_dereference(sdata->u.vlan.sta); -- cgit v1.2.3