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Diffstat (limited to 'net/mac80211/status.c')
-rw-r--r--net/mac80211/status.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 52a152b01b06..1ee85c402439 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -11,6 +11,7 @@
#include <linux/export.h>
#include <linux/etherdevice.h>
+#include <linux/time.h>
#include <net/mac80211.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
@@ -463,6 +464,77 @@ static void ieee80211_report_used_skb(struct ieee80211_local *local,
}
/*
+ * Measure Tx frame completion and removal 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 remove the skb.
+ */
+static void ieee80211_tx_latency_end_msrmnt(struct ieee80211_local *local,
+ struct sk_buff *skb,
+ struct sta_info *sta,
+ struct ieee80211_hdr *hdr)
+{
+ ktime_t skb_dprt;
+ struct timespec dprt_time;
+ u32 msrmnt;
+ u16 tid;
+ u8 *qc;
+ int i, bin_range_count, bin_count;
+ u32 *bin_ranges;
+ __le16 fc;
+ struct ieee80211_tx_latency_stat *tx_lat;
+ struct ieee80211_tx_latency_bin_ranges *tx_latency;
+ ktime_t skb_arv = skb->tstamp;
+
+ tx_latency = rcu_dereference(local->tx_latency);
+
+ /* assert Tx latency stats are enabled & frame arrived when enabled */
+ if (!tx_latency || !ktime_to_ns(skb_arv))
+ return;
+
+ fc = hdr->frame_control;
+
+ if (!ieee80211_is_data(fc)) /* make sure it is a data frame */
+ return;
+
+ /* get frame tid */
+ if (ieee80211_is_data_qos(hdr->frame_control)) {
+ qc = ieee80211_get_qos_ctl(hdr);
+ tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
+ } else {
+ tid = 0;
+ }
+
+ tx_lat = &sta->tx_lat[tid];
+
+ ktime_get_ts(&dprt_time); /* time stamp completion time */
+ skb_dprt = ktime_set(dprt_time.tv_sec, dprt_time.tv_nsec);
+ msrmnt = ktime_to_ms(ktime_sub(skb_dprt, skb_arv));
+
+ if (tx_lat->max < msrmnt) /* update stats */
+ tx_lat->max = msrmnt;
+ tx_lat->counter++;
+ tx_lat->sum += msrmnt;
+
+ if (!tx_lat->bins) /* bins not activated */
+ return;
+
+ /* count how many Tx frames transmitted with the appropriate latency */
+ bin_range_count = tx_latency->n_ranges;
+ bin_ranges = tx_latency->ranges;
+ bin_count = tx_lat->bin_count;
+
+ for (i = 0; i < bin_range_count; i++) {
+ if (msrmnt <= bin_ranges[i]) {
+ tx_lat->bins[i]++;
+ break;
+ }
+ }
+ if (i == bin_range_count) /* msrmnt is bigger than the biggest range */
+ tx_lat->bins[i]++;
+}
+
+/*
* Use a static threshold for now, best value to be determined
* by testing ...
* Should it depend on:
@@ -620,6 +692,12 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
if (acked)
sta->last_ack_signal = info->status.ack_signal;
+
+ /*
+ * Measure frame removal for tx latency
+ * statistics calculation
+ */
+ ieee80211_tx_latency_end_msrmnt(local, skb, sta, hdr);
}
rcu_read_unlock();