mac80211: provide race-free 64-bit traffic counters

Make the TX bytes/packets counters race-free by keeping them per AC so concurrent TX on queues can't cause lost or wrong updates. This works since each station belongs to a single interface. While at it also make the bytes counters 64-bit. Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: provide race-free 64-bit traffic counters
Make the TX bytes/packets counters race-free by keeping them per AC so concurrent TX on queues can't cause lost or wrong updates. This works since each station belongs to a single interface. While at it also make the bytes counters 64-bit. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Johannes Berg
1 parent 87f59c70ce
Showing 3 changed files with 25 additions and 14 deletions Side-by-side Diff
net/mac80211/cfg.c
net/mac80211/sta_info.h
net/mac80211/tx.c
@@ -445,12 +445,14 @@
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	struct ieee80211_local *local = sdata->local;
 	struct timespec uptime;
+	u64 packets = 0;
+	int ac;
  
 	sinfo->generation = sdata->local->sta_generation;
  
 	sinfo->filled = STATION_INFO_INACTIVE_TIME |
-			STATION_INFO_RX_BYTES |
-			STATION_INFO_TX_BYTES |
+			STATION_INFO_RX_BYTES64 |
+			STATION_INFO_TX_BYTES64 |
 			STATION_INFO_RX_PACKETS |
 			STATION_INFO_TX_PACKETS |
 			STATION_INFO_TX_RETRIES |
  
  
@@ -467,10 +469,14 @@
 	sinfo->connected_time = uptime.tv_sec - sta->last_connected;
  
 	sinfo->inactive_time = jiffies_to_msecs(jiffies - sta->last_rx);
+	sinfo->tx_bytes = 0;
+	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
+		sinfo->tx_bytes += sta->tx_bytes[ac];
+		packets += sta->tx_packets[ac];
+	}
+	sinfo->tx_packets = packets;
 	sinfo->rx_bytes = sta->rx_bytes;
-	sinfo->tx_bytes = sta->tx_bytes;
 	sinfo->rx_packets = sta->rx_packets;
-	sinfo->tx_packets = sta->tx_packets;
 	sinfo->tx_retries = sta->tx_retry_count;
 	sinfo->tx_failed = sta->tx_retry_failed;
 	sinfo->rx_dropped_misc = sta->rx_dropped;
@@ -598,8 +604,8 @@
 		data[i++] += sta->rx_fragments;		\
 		data[i++] += sta->rx_dropped;		\
 							\
-		data[i++] += sta->tx_packets;		\
-		data[i++] += sta->tx_bytes;		\
+		data[i++] += sinfo.tx_packets;		\
+		data[i++] += sinfo.tx_bytes;		\
 		data[i++] += sta->tx_fragments;		\
 		data[i++] += sta->tx_filtered_count;	\
 		data[i++] += sta->tx_retry_failed;	\
  
@@ -621,13 +627,14 @@
 		if (!(sta && !WARN_ON(sta->sdata->dev != dev)))
 			goto do_survey;
  
+		sinfo.filled = 0;
+		sta_set_sinfo(sta, &sinfo);
+
 		i = 0;
 		ADD_STA_STATS(sta);
  
 		data[i++] = sta->sta_state;
  
-		sinfo.filled = 0;
-		sta_set_sinfo(sta, &sinfo);
  
 		if (sinfo.filled & STATION_INFO_TX_BITRATE)
 			data[i] = 100000 *
@@ -333,7 +333,8 @@
 	unsigned long driver_buffered_tids;
  
 	/* Updated from RX path only, no locking requirements */
-	unsigned long rx_packets, rx_bytes;
+	unsigned long rx_packets;
+	u64 rx_bytes;
 	unsigned long wep_weak_iv_count;
 	unsigned long last_rx;
 	long last_connected;
@@ -353,9 +354,9 @@
 	unsigned int fail_avg;
  
 	/* Updated from TX path only, no locking requirements */
-	unsigned long tx_packets;
-	unsigned long tx_bytes;
-	unsigned long tx_fragments;
+	u32 tx_fragments;
+	u64 tx_packets[IEEE80211_NUM_ACS];
+	u64 tx_bytes[IEEE80211_NUM_ACS];
 	struct ieee80211_tx_rate last_tx_rate;
 	int last_rx_rate_idx;
 	u32 last_rx_rate_flag;
@@ -991,15 +991,18 @@
 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
 {
 	struct sk_buff *skb;
+	int ac = -1;
  
 	if (!tx->sta)
 		return TX_CONTINUE;
  
-	tx->sta->tx_packets++;
 	skb_queue_walk(&tx->skbs, skb) {
+		ac = skb_get_queue_mapping(skb);
 		tx->sta->tx_fragments++;
-		tx->sta->tx_bytes += skb->len;
+		tx->sta->tx_bytes[ac] += skb->len;
 	}
+	if (ac >= 0)
+		tx->sta->tx_packets[ac]++;
  
 	return TX_CONTINUE;
 }
...	...	@@ -445,12 +445,14 @@
445	445	struct ieee80211_sub_if_data *sdata = sta->sdata;
446	446	struct ieee80211_local *local = sdata->local;
447	447	struct timespec uptime;
	448	+ u64 packets = 0;
	449	+ int ac;
448	450
449	451	sinfo->generation = sdata->local->sta_generation;
450	452
451	453	sinfo->filled = STATION_INFO_INACTIVE_TIME \|
452		- STATION_INFO_RX_BYTES \|
453		- STATION_INFO_TX_BYTES \|
	454	+ STATION_INFO_RX_BYTES64 \|
	455	+ STATION_INFO_TX_BYTES64 \|
454	456	STATION_INFO_RX_PACKETS \|
455	457	STATION_INFO_TX_PACKETS \|
456	458	STATION_INFO_TX_RETRIES \|
457	459
458	460
...	...	@@ -467,10 +469,14 @@
467	469	sinfo->connected_time = uptime.tv_sec - sta->last_connected;
468	470
469	471	sinfo->inactive_time = jiffies_to_msecs(jiffies - sta->last_rx);
	472	+ sinfo->tx_bytes = 0;
	473	+ for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
	474	+ sinfo->tx_bytes += sta->tx_bytes[ac];
	475	+ packets += sta->tx_packets[ac];
	476	+ }
	477	+ sinfo->tx_packets = packets;
470	478	sinfo->rx_bytes = sta->rx_bytes;
471		- sinfo->tx_bytes = sta->tx_bytes;
472	479	sinfo->rx_packets = sta->rx_packets;
473		- sinfo->tx_packets = sta->tx_packets;
474	480	sinfo->tx_retries = sta->tx_retry_count;
475	481	sinfo->tx_failed = sta->tx_retry_failed;
476	482	sinfo->rx_dropped_misc = sta->rx_dropped;
...	...	@@ -598,8 +604,8 @@
598	604	data[i++] += sta->rx_fragments; \
599	605	data[i++] += sta->rx_dropped; \
600	606	\
601		- data[i++] += sta->tx_packets; \
602		- data[i++] += sta->tx_bytes; \
	607	+ data[i++] += sinfo.tx_packets; \
	608	+ data[i++] += sinfo.tx_bytes; \
603	609	data[i++] += sta->tx_fragments; \
604	610	data[i++] += sta->tx_filtered_count; \
605	611	data[i++] += sta->tx_retry_failed; \
606	612
...	...	@@ -621,13 +627,14 @@
621	627	if (!(sta && !WARN_ON(sta->sdata->dev != dev)))
622	628	goto do_survey;
623	629
	630	+ sinfo.filled = 0;
	631	+ sta_set_sinfo(sta, &sinfo);
	632	+
624	633	i = 0;
625	634	ADD_STA_STATS(sta);
626	635
627	636	data[i++] = sta->sta_state;
628	637
629		- sinfo.filled = 0;
630		- sta_set_sinfo(sta, &sinfo);
631	638
632	639	if (sinfo.filled & STATION_INFO_TX_BITRATE)
633	640	data[i] = 100000 *
...	...	@@ -333,7 +333,8 @@
333	333	unsigned long driver_buffered_tids;
334	334
335	335	/* Updated from RX path only, no locking requirements */
336		- unsigned long rx_packets, rx_bytes;
	336	+ unsigned long rx_packets;
	337	+ u64 rx_bytes;
337	338	unsigned long wep_weak_iv_count;
338	339	unsigned long last_rx;
339	340	long last_connected;
...	...	@@ -353,9 +354,9 @@
353	354	unsigned int fail_avg;
354	355
355	356	/* Updated from TX path only, no locking requirements */
356		- unsigned long tx_packets;
357		- unsigned long tx_bytes;
358		- unsigned long tx_fragments;
	357	+ u32 tx_fragments;
	358	+ u64 tx_packets[IEEE80211_NUM_ACS];
	359	+ u64 tx_bytes[IEEE80211_NUM_ACS];
359	360	struct ieee80211_tx_rate last_tx_rate;
360	361	int last_rx_rate_idx;
361	362	u32 last_rx_rate_flag;
...	...	@@ -991,15 +991,18 @@
991	991	ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
992	992	{
993	993	struct sk_buff *skb;
	994	+ int ac = -1;
994	995
995	996	if (!tx->sta)
996	997	return TX_CONTINUE;
997	998
998		- tx->sta->tx_packets++;
999	999	skb_queue_walk(&tx->skbs, skb) {
	1000	+ ac = skb_get_queue_mapping(skb);
1000	1001	tx->sta->tx_fragments++;
1001		- tx->sta->tx_bytes += skb->len;
	1002	+ tx->sta->tx_bytes[ac] += skb->len;
1002	1003	}
	1004	+ if (ac >= 0)
	1005	+ tx->sta->tx_packets[ac]++;
1003	1006
1004	1007	return TX_CONTINUE;
1005	1008	}