mac80211: remove channel use statistics

The useless channel use statistics are quite a lot of code, currently
use integer divisions in the packet fast path, are rather inaccurate
since they do not account for retries and finally nobody even cares.
Hence, remove them completely.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 3 insertions, 59 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index cf0de3b0fe2..9400a9766a7 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -387,51 +387,9 @@ static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
 }
 
 
-static u32 ieee80211_rx_load_stats(struct ieee80211_local *local,
-				   struct sk_buff *skb,
-				   struct ieee80211_rx_status *status,
-				   struct ieee80211_rate *rate)
-{
-	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-	u32 load = 0, hdrtime;
-
-	/* Estimate total channel use caused by this frame */
-
-	/* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
-	 * 1 usec = 1/8 * (1080 / 10) = 13.5 */
-
-	if (status->band == IEEE80211_BAND_5GHZ ||
-	    (status->band == IEEE80211_BAND_5GHZ &&
-	     rate->flags & IEEE80211_RATE_ERP_G))
-		hdrtime = CHAN_UTIL_HDR_SHORT;
-	else
-		hdrtime = CHAN_UTIL_HDR_LONG;
-
-	load = hdrtime;
-	if (!is_multicast_ether_addr(hdr->addr1))
-		load += hdrtime;
-
-	/* TODO: optimise again */
-	load += skb->len * CHAN_UTIL_RATE_LCM / rate->bitrate;
-
-	/* Divide channel_use by 8 to avoid wrapping around the counter */
-	load >>= CHAN_UTIL_SHIFT;
-
-	return load;
-}
-
 /* rx handlers */
 
 static ieee80211_rx_result
-ieee80211_rx_h_if_stats(struct ieee80211_rx_data *rx)
-{
-	if (rx->sta)
-		rx->sta->channel_use_raw += rx->load;
-	rx->sdata->channel_use_raw += rx->load;
-	return RX_CONTINUE;
-}
-
-static ieee80211_rx_result
 ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
 {
 	struct ieee80211_local *local = rx->local;
@@ -1780,7 +1738,6 @@ static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx)
 typedef ieee80211_rx_result (*ieee80211_rx_handler)(struct ieee80211_rx_data *);
 static ieee80211_rx_handler ieee80211_rx_handlers[] =
 {
-	ieee80211_rx_h_if_stats,
 	ieee80211_rx_h_passive_scan,
 	ieee80211_rx_h_check,
 	ieee80211_rx_h_decrypt,
@@ -1939,7 +1896,6 @@ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
 static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 					 struct sk_buff *skb,
 					 struct ieee80211_rx_status *status,
-					 u32 load,
 					 struct ieee80211_rate *rate)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
@@ -1958,7 +1914,6 @@ static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
 	rx.local = local;
 
 	rx.status = status;
-	rx.load = load;
 	rx.rate = rate;
 	rx.fc = le16_to_cpu(hdr->frame_control);
 	type = rx.fc & IEEE80211_FCTL_FTYPE;
@@ -2067,7 +2022,6 @@ u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 	struct ieee80211_rx_status status;
 	u16 head_seq_num, buf_size;
 	int index;
-	u32 pkt_load;
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_rate *rate;
 
@@ -2102,12 +2056,9 @@ u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 					sizeof(status));
 				sband = local->hw.wiphy->bands[status.band];
 				rate = &sband->bitrates[status.rate_idx];
-				pkt_load = ieee80211_rx_load_stats(local,
-						tid_agg_rx->reorder_buf[index],
-						&status, rate);
 				__ieee80211_rx_handle_packet(hw,
 					tid_agg_rx->reorder_buf[index],
-					&status, pkt_load, rate);
+					&status, rate);
 				tid_agg_rx->stored_mpdu_num--;
 				tid_agg_rx->reorder_buf[index] = NULL;
 			}
@@ -2149,11 +2100,8 @@ u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
 			sizeof(status));
 		sband = local->hw.wiphy->bands[status.band];
 		rate = &sband->bitrates[status.rate_idx];
-		pkt_load = ieee80211_rx_load_stats(local,
-					tid_agg_rx->reorder_buf[index],
-					&status, rate);
 		__ieee80211_rx_handle_packet(hw, tid_agg_rx->reorder_buf[index],
-					     &status, pkt_load, rate);
+					     &status, rate);
 		tid_agg_rx->stored_mpdu_num--;
 		tid_agg_rx->reorder_buf[index] = NULL;
 		tid_agg_rx->head_seq_num = seq_inc(tid_agg_rx->head_seq_num);
@@ -2232,7 +2180,6 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
 		    struct ieee80211_rx_status *status)
 {
 	struct ieee80211_local *local = hw_to_local(hw);
-	u32 pkt_load;
 	struct ieee80211_rate *rate = NULL;
 	struct ieee80211_supported_band *sband;
 
@@ -2272,11 +2219,8 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
 		return;
 	}
 
-	pkt_load = ieee80211_rx_load_stats(local, skb, status, rate);
-	local->channel_use_raw += pkt_load;
-
 	if (!ieee80211_rx_reorder_ampdu(local, skb))
-		__ieee80211_rx_handle_packet(hw, skb, status, pkt_load, rate);
+		__ieee80211_rx_handle_packet(hw, skb, status, rate);
 
 	rcu_read_unlock();
 }