[PATCH 01/10] mac80211: minstrel_ht: move supported bitrate mask out of group data

[PATCH 01/10] mac80211: minstrel_ht: move supported bitrate mask out of group data

[Felix Fietkau]

Improves dcache footprint by ensuring that fewer cache lines need to be
touched.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel_ht.c         | 30 +++++++++++++++---------------
 net/mac80211/rc80211_minstrel_ht.h         |  6 +++---
 net/mac80211/rc80211_minstrel_ht_debugfs.c |  8 ++++----
 3 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 30fbabf..ed8a34d 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -301,7 +301,7 @@ minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 				break;
 
 		/* short preamble */
-		if (!(mi->groups[group].supported & BIT(idx)))
+		if (!(mi->supported[group] & BIT(idx)))
 			idx += 4;
 	}
 	return &mi->groups[group].rates[idx];
@@ -486,7 +486,7 @@ minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
 			  MCS_GROUP_RATES].streams;
 	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
 		mg = &mi->groups[group];
-		if (!mg->supported || group == MINSTREL_CCK_GROUP)
+		if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
 			continue;
 
 		tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
@@ -540,7 +540,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
 
 		mg = &mi->groups[group];
-		if (!mg->supported)
+		if (!mi->supported[group])
 			continue;
 
 		mi->sample_count++;
@@ -550,7 +550,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 			tmp_group_tp_rate[j] = group;
 
 		for (i = 0; i < MCS_GROUP_RATES; i++) {
-			if (!(mg->supported & BIT(i)))
+			if (!(mi->supported[group] & BIT(i)))
 				continue;
 
 			index = MCS_GROUP_RATES * group + i;
@@ -636,7 +636,7 @@ minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
 		mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
 		mg = &mi->groups[mi->sample_group];
 
-		if (!mg->supported)
+		if (!mi->supported[mi->sample_group])
 			continue;
 
 		if (++mg->index >= MCS_GROUP_RATES) {
@@ -657,7 +657,7 @@ minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
 	while (group > 0) {
 		group--;
 
-		if (!mi->groups[group].supported)
+		if (!mi->supported[group])
 			continue;
 
 		if (minstrel_mcs_groups[group].streams >
@@ -994,7 +994,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 	sample_idx = sample_table[mg->column][mg->index];
 	minstrel_set_next_sample_idx(mi);
 
-	if (!(mg->supported & BIT(sample_idx)))
+	if (!(mi->supported[sample_group] & BIT(sample_idx)))
 		return -1;
 
 	mrs = &mg->rates[sample_idx];
@@ -1052,7 +1052,7 @@ static void
 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
 				    struct minstrel_ht_sta *mi, bool val)
 {
-	u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
+	u8 supported = mi->supported[MINSTREL_CCK_GROUP];
 
 	if (!supported || !mi->cck_supported_short)
 		return;
@@ -1061,7 +1061,7 @@ minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
 		return;
 
 	supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
-	mi->groups[MINSTREL_CCK_GROUP].supported = supported;
+	mi->supported[MINSTREL_CCK_GROUP] = supported;
 }
 
 static void
@@ -1154,7 +1154,7 @@ minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 			mi->cck_supported_short |= BIT(i);
 	}
 
-	mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
+	mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
 }
 
 static void
@@ -1224,7 +1224,7 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
 		u32 gflags = minstrel_mcs_groups[i].flags;
 		int bw, nss;
 
-		mi->groups[i].supported = 0;
+		mi->supported[i] = 0;
 		if (i == MINSTREL_CCK_GROUP) {
 			minstrel_ht_update_cck(mp, mi, sband, sta);
 			continue;
@@ -1256,8 +1256,8 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
 			if (use_vht && minstrel_vht_only)
 				continue;
 #endif
-			mi->groups[i].supported = mcs->rx_mask[nss - 1];
-			if (mi->groups[i].supported)
+			mi->supported[i] = mcs->rx_mask[nss - 1];
+			if (mi->supported[i])
 				n_supported++;
 			continue;
 		}
@@ -1283,10 +1283,10 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
 		else
 			bw = BW_20;
 
-		mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss,
+		mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
 				vht_cap->vht_mcs.tx_mcs_map);
 
-		if (mi->groups[i].supported)
+		if (mi->supported[i])
 			n_supported++;
 	}
 
diff --git a/net/mac80211/rc80211_minstrel_ht.h b/net/mac80211/rc80211_minstrel_ht.h
index e8b52a9..de1646c 100644
--- a/net/mac80211/rc80211_minstrel_ht.h
+++ b/net/mac80211/rc80211_minstrel_ht.h
@@ -52,9 +52,6 @@ struct minstrel_mcs_group_data {
 	u8 index;
 	u8 column;
 
-	/* bitfield of supported MCS rates of this group */
-	u16 supported;
-
 	/* sorted rate set within a MCS group*/
 	u16 max_group_tp_rate[MAX_THR_RATES];
 	u16 max_group_prob_rate;
@@ -101,6 +98,9 @@ struct minstrel_ht_sta {
 	u8 cck_supported;
 	u8 cck_supported_short;
 
+	/* Bitfield of supported MCS rates of all groups */
+	u16 supported[MINSTREL_GROUPS_NB];
+
 	/* MCS rate group info and statistics */
 	struct minstrel_mcs_group_data groups[MINSTREL_GROUPS_NB];
 };
diff --git a/net/mac80211/rc80211_minstrel_ht_debugfs.c b/net/mac80211/rc80211_minstrel_ht_debugfs.c
index 5320e35..1942d4b 100644
--- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
@@ -24,7 +24,7 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 	char gimode = 'L';
 	u32 gflags;
 
-	if (!mi->groups[i].supported)
+	if (!mi->supported[i])
 		return p;
 
 	mg = &minstrel_mcs_groups[i];
@@ -42,7 +42,7 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		static const int bitrates[4] = { 10, 20, 55, 110 };
 		int idx = i * MCS_GROUP_RATES + j;
 
-		if (!(mi->groups[i].supported & BIT(j)))
+		if (!(mi->supported[i] & BIT(j)))
 			continue;
 
 		if (gflags & IEEE80211_TX_RC_MCS) {
@@ -170,7 +170,7 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 	char gimode = 'L';
 	u32 gflags;
 
-	if (!mi->groups[i].supported)
+	if (!mi->supported[i])
 		return p;
 
 	mg = &minstrel_mcs_groups[i];
@@ -188,7 +188,7 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		static const int bitrates[4] = { 10, 20, 55, 110 };
 		int idx = i * MCS_GROUP_RATES + j;
 
-		if (!(mi->groups[i].supported & BIT(j)))
+		if (!(mi->supported[i] & BIT(j)))
 			continue;
 
 		if (gflags & IEEE80211_TX_RC_MCS) {
-- 
2.10.1

[PATCH 02/10] mac80211: minstrel_ht: move short preamble check out of get_rate

[Felix Fietkau]

Test short preamble support in minstrel_ht_update_caps instead of
looking at the per-packet flag. Makes the code more efficient.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel_ht.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index ed8a34d..ae45dcb 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -14,6 +14,7 @@
 #include <linux/ieee80211.h>
 #include <net/mac80211.h>
 #include "rate.h"
+#include "sta_info.h"
 #include "rc80211_minstrel.h"
 #include "rc80211_minstrel_ht.h"
 
@@ -1049,22 +1050,6 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 }
 
 static void
-minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
-				    struct minstrel_ht_sta *mi, bool val)
-{
-	u8 supported = mi->supported[MINSTREL_CCK_GROUP];
-
-	if (!supported || !mi->cck_supported_short)
-		return;
-
-	if (supported & (mi->cck_supported_short << (val * 4)))
-		return;
-
-	supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
-	mi->supported[MINSTREL_CCK_GROUP] = supported;
-}
-
-static void
 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
                      struct ieee80211_tx_rate_control *txrc)
 {
@@ -1087,7 +1072,6 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
 		minstrel_aggr_check(sta, txrc->skb);
 
 	info->flags |= mi->tx_flags;
-	minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
 
 #ifdef CONFIG_MAC80211_DEBUGFS
 	if (mp->fixed_rate_idx != -1)
@@ -1168,6 +1152,7 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
 	struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
 	u16 sta_cap = sta->ht_cap.cap;
 	struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
+	struct sta_info *sinfo = container_of(sta, struct sta_info, sta);
 	int use_vht;
 	int n_supported = 0;
 	int ack_dur;
@@ -1293,6 +1278,9 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
 	if (!n_supported)
 		goto use_legacy;
 
+	if (test_sta_flag(sinfo, WLAN_STA_SHORT_PREAMBLE))
+		mi->cck_supported_short |= mi->cck_supported_short << 4;
+
 	/* create an initial rate table with the lowest supported rates */
 	minstrel_ht_update_stats(mp, mi);
 	minstrel_ht_update_rates(mp, mi);
-- 
2.10.1

[PATCH 03/10] mac80211: minstrel_ht: make att_hist and succ_hist u32 instead of u64

[Felix Fietkau]

They are only used for debugging purposes and take a very long time to
overflow. Visibly reduces the size of the per-sta rate control data.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index c230bbe..209961c 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -59,7 +59,7 @@ struct minstrel_rate_stats {
 	u16 success, last_success;
 
 	/* total attempts/success counters */
-	u64 att_hist, succ_hist;
+	u32 att_hist, succ_hist;
 
 	/* statistis of packet delivery probability
 	 *  cur_prob  - current prob within last update intervall
-- 
2.10.1

[PATCH 04/10] mac80211: check for MCS in ieee80211_duration before fetching chanctx

[Felix Fietkau]

Makes the code a bit more efficient

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/tx.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 058652d..4dea18b 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -64,6 +64,10 @@ static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
 	struct ieee80211_chanctx_conf *chanctx_conf;
 	u32 rate_flags = 0;
 
+	/* assume HW handles this */
+	if (tx->rate.flags & (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))
+		return 0;
+
 	rcu_read_lock();
 	chanctx_conf = rcu_dereference(tx->sdata->vif.chanctx_conf);
 	if (chanctx_conf) {
@@ -72,10 +76,6 @@ static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
 	}
 	rcu_read_unlock();
 
-	/* assume HW handles this */
-	if (tx->rate.flags & (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))
-		return 0;
-
 	/* uh huh? */
 	if (WARN_ON_ONCE(tx->rate.idx < 0))
 		return 0;
-- 
2.10.1

[PATCH 05/10] mac80211: minstrel: remove cur_prob from debugfs

[Felix Fietkau]

This field is redundant, because it is simply last success divided by
last attempt count. Removing it from the rate stats struct saves about
1.2 KiB per HT station.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel.c            | 10 ++++++----
 net/mac80211/rc80211_minstrel.h            |  2 --
 net/mac80211/rc80211_minstrel_debugfs.c    | 16 ++++++----------
 net/mac80211/rc80211_minstrel_ht_debugfs.c | 16 ++++++----------
 4 files changed, 18 insertions(+), 26 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 14c5ba3..a284ea0 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -159,21 +159,23 @@ minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 void
 minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs)
 {
+	unsigned int cur_prob;
+
 	if (unlikely(mrs->attempts > 0)) {
 		mrs->sample_skipped = 0;
-		mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
+		cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
 		if (unlikely(!mrs->att_hist)) {
-			mrs->prob_ewma = mrs->cur_prob;
+			mrs->prob_ewma = cur_prob;
 		} else {
 			/* update exponential weighted moving variance */
 			mrs->prob_ewmsd = minstrel_ewmsd(mrs->prob_ewmsd,
-							 mrs->cur_prob,
+							 cur_prob,
 							 mrs->prob_ewma,
 							 EWMA_LEVEL);
 
 			/*update exponential weighted moving avarage */
 			mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma,
-						       mrs->cur_prob,
+						       cur_prob,
 						       EWMA_LEVEL);
 		}
 		mrs->att_hist += mrs->attempts;
diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 209961c..94b89b1 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -62,10 +62,8 @@ struct minstrel_rate_stats {
 	u32 att_hist, succ_hist;
 
 	/* statistis of packet delivery probability
-	 *  cur_prob  - current prob within last update intervall
 	 *  prob_ewma - exponential weighted moving average of prob
 	 *  prob_ewmsd - exp. weighted moving standard deviation of prob */
-	unsigned int cur_prob;
 	unsigned int prob_ewma;
 	u16 prob_ewmsd;
 
diff --git a/net/mac80211/rc80211_minstrel_debugfs.c b/net/mac80211/rc80211_minstrel_debugfs.c
index 820b0ab..ca0bafd 100644
--- a/net/mac80211/rc80211_minstrel_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_debugfs.c
@@ -75,7 +75,7 @@ minstrel_stats_open(struct inode *inode, struct file *file)
 {
 	struct minstrel_sta_info *mi = inode->i_private;
 	struct minstrel_debugfs_info *ms;
-	unsigned int i, tp_max, tp_avg, prob, eprob;
+	unsigned int i, tp_max, tp_avg, eprob;
 	char *p;
 
 	ms = kmalloc(2048, GFP_KERNEL);
@@ -86,9 +86,9 @@ minstrel_stats_open(struct inode *inode, struct file *file)
 	p = ms->buf;
 	p += sprintf(p, "\n");
 	p += sprintf(p,
-		     "best   __________rate_________    ________statistics________    ________last_______    ______sum-of________\n");
+		     "best   __________rate_________    ________statistics________    ____last_____    ______sum-of________\n");
 	p += sprintf(p,
-		     "rate  [name idx airtime max_tp]  [avg(tp) avg(prob) sd(prob)]  [prob.|retry|suc|att]  [#success | #attempts]\n");
+		     "rate  [name idx airtime max_tp]  [avg(tp) avg(prob) sd(prob)]  [retry|suc|att]  [#success | #attempts]\n");
 
 	for (i = 0; i < mi->n_rates; i++) {
 		struct minstrel_rate *mr = &mi->r[i];
@@ -107,17 +107,15 @@ minstrel_stats_open(struct inode *inode, struct file *file)
 
 		tp_max = minstrel_get_tp_avg(mr, MINSTREL_FRAC(100,100));
 		tp_avg = minstrel_get_tp_avg(mr, mrs->prob_ewma);
-		prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
 		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
 
 		p += sprintf(p, "%4u.%1u    %4u.%1u     %3u.%1u    %3u.%1u"
-				"     %3u.%1u %3u   %3u %-3u   "
+				"     %3u   %3u %-3u   "
 				"%9llu   %-9llu\n",
 				tp_max / 10, tp_max % 10,
 				tp_avg / 10, tp_avg % 10,
 				eprob / 10, eprob % 10,
 				mrs->prob_ewmsd / 10, mrs->prob_ewmsd % 10,
-				prob / 10, prob % 10,
 				mrs->retry_count,
 				mrs->last_success,
 				mrs->last_attempts,
@@ -148,7 +146,7 @@ minstrel_stats_csv_open(struct inode *inode, struct file *file)
 {
 	struct minstrel_sta_info *mi = inode->i_private;
 	struct minstrel_debugfs_info *ms;
-	unsigned int i, tp_max, tp_avg, prob, eprob;
+	unsigned int i, tp_max, tp_avg, eprob;
 	char *p;
 
 	ms = kmalloc(2048, GFP_KERNEL);
@@ -175,16 +173,14 @@ minstrel_stats_csv_open(struct inode *inode, struct file *file)
 
 		tp_max = minstrel_get_tp_avg(mr, MINSTREL_FRAC(100,100));
 		tp_avg = minstrel_get_tp_avg(mr, mrs->prob_ewma);
-		prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
 		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
 
-		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u.%u,%u.%u,%u,%u,%u,"
+		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u.%u,%u,%u,%u,"
 				"%llu,%llu,%d,%d\n",
 				tp_max / 10, tp_max % 10,
 				tp_avg / 10, tp_avg % 10,
 				eprob / 10, eprob % 10,
 				mrs->prob_ewmsd / 10, mrs->prob_ewmsd % 10,
-				prob / 10, prob % 10,
 				mrs->retry_count,
 				mrs->last_success,
 				mrs->last_attempts,
diff --git a/net/mac80211/rc80211_minstrel_ht_debugfs.c b/net/mac80211/rc80211_minstrel_ht_debugfs.c
index 1942d4b..0cecd23 100644
--- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
@@ -19,7 +19,7 @@ static char *
 minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 {
 	const struct mcs_group *mg;
-	unsigned int j, tp_max, tp_avg, prob, eprob, tx_time;
+	unsigned int j, tp_max, tp_avg, eprob, tx_time;
 	char htmode = '2';
 	char gimode = 'L';
 	u32 gflags;
@@ -83,17 +83,15 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 
 		tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
 		tp_avg = minstrel_ht_get_tp_avg(mi, i, j, mrs->prob_ewma);
-		prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
 		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
 
 		p += sprintf(p, "%4u.%1u    %4u.%1u     %3u.%1u    %3u.%1u"
-				"     %3u.%1u %3u   %3u %-3u   "
+				"     %3u   %3u %-3u   "
 				"%9llu   %-9llu\n",
 				tp_max / 10, tp_max % 10,
 				tp_avg / 10, tp_avg % 10,
 				eprob / 10, eprob % 10,
 				mrs->prob_ewmsd / 10, mrs->prob_ewmsd % 10,
-				prob / 10, prob % 10,
 				mrs->retry_count,
 				mrs->last_success,
 				mrs->last_attempts,
@@ -130,9 +128,9 @@ minstrel_ht_stats_open(struct inode *inode, struct file *file)
 
 	p += sprintf(p, "\n");
 	p += sprintf(p,
-		     "              best   ____________rate__________    ________statistics________    ________last_______    ______sum-of________\n");
+		     "              best   ____________rate__________    ________statistics________    _____last____    ______sum-of________\n");
 	p += sprintf(p,
-		     "mode guard #  rate  [name   idx airtime  max_tp]  [avg(tp) avg(prob) sd(prob)]  [prob.|retry|suc|att]  [#success | #attempts]\n");
+		     "mode guard #  rate  [name   idx airtime  max_tp]  [avg(tp) avg(prob) sd(prob)]  [retry|suc|att]  [#success | #attempts]\n");
 
 	p = minstrel_ht_stats_dump(mi, MINSTREL_CCK_GROUP, p);
 	for (i = 0; i < MINSTREL_CCK_GROUP; i++)
@@ -165,7 +163,7 @@ static char *
 minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 {
 	const struct mcs_group *mg;
-	unsigned int j, tp_max, tp_avg, prob, eprob, tx_time;
+	unsigned int j, tp_max, tp_avg, eprob, tx_time;
 	char htmode = '2';
 	char gimode = 'L';
 	u32 gflags;
@@ -226,16 +224,14 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 
 		tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
 		tp_avg = minstrel_ht_get_tp_avg(mi, i, j, mrs->prob_ewma);
-		prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
 		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
 
-		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u.%u,%u.%u,%u,%u,"
+		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u.%u,%u,%u,"
 				"%u,%llu,%llu,",
 				tp_max / 10, tp_max % 10,
 				tp_avg / 10, tp_avg % 10,
 				eprob / 10, eprob % 10,
 				mrs->prob_ewmsd / 10, mrs->prob_ewmsd % 10,
-				prob / 10, prob % 10,
 				mrs->retry_count,
 				mrs->last_success,
 				mrs->last_attempts,
-- 
2.10.1

[PATCH 06/10] mac80211: minstrel: reduce MINSTREL_SCALE

[Felix Fietkau]

The loss of a bit of extra precision does not hurt the calculation, 12
bits is still enough to calculate probabilities well. Reducing the scale
makes it easier to avoid overflows

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 94b89b1..03716fd 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -14,7 +14,7 @@
 #define SAMPLE_COLUMNS	10	/* number of columns in sample table */
 
 /* scaled fraction values */
-#define MINSTREL_SCALE  16
+#define MINSTREL_SCALE  12
 #define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
 #define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
 
-- 
2.10.1

[PATCH 07/10] mac80211: minstrel: store probability variance instead of standard deviation

[Felix Fietkau]

This avoids the costly int_sqrt calls in the statistics update and moves
it to the debugfs code instead.
This also fixes an overflow in the previous standard deviation
calculation.

Signed-off-by: Thomas Huehn <thomas.huehn@evernet-eg.de>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel.c            |  8 ++++----
 net/mac80211/rc80211_minstrel.h            | 25 ++++++++++++++-----------
 net/mac80211/rc80211_minstrel_debugfs.c    |  8 ++++++--
 net/mac80211/rc80211_minstrel_ht_debugfs.c |  8 ++++++--
 4 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index a284ea0..11a4cc3 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -168,10 +168,10 @@ minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs)
 			mrs->prob_ewma = cur_prob;
 		} else {
 			/* update exponential weighted moving variance */
-			mrs->prob_ewmsd = minstrel_ewmsd(mrs->prob_ewmsd,
-							 cur_prob,
-							 mrs->prob_ewma,
-							 EWMA_LEVEL);
+			mrs->prob_ewmv = minstrel_ewmv(mrs->prob_ewmv,
+							cur_prob,
+							mrs->prob_ewma,
+							EWMA_LEVEL);
 
 			/*update exponential weighted moving avarage */
 			mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma,
diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 03716fd..ea86e67 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -36,21 +36,16 @@ minstrel_ewma(int old, int new, int weight)
 }
 
 /*
- * Perform EWMSD (Exponentially Weighted Moving Standard Deviation) calculation
+ * Perform EWMV (Exponentially Weighted Moving Variance) calculation
  */
 static inline int
-minstrel_ewmsd(int old_ewmsd, int cur_prob, int prob_ewma, int weight)
+minstrel_ewmv(int old_ewmv, int cur_prob, int prob_ewma, int weight)
 {
-	int diff, incr, tmp_var;
+	int diff, incr;
 
-	/* calculate exponential weighted moving variance */
-	diff = MINSTREL_TRUNC((cur_prob - prob_ewma) * 1000000);
+	diff = cur_prob - prob_ewma;
 	incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
-	tmp_var = old_ewmsd * old_ewmsd;
-	tmp_var = weight * (tmp_var + diff * incr / 1000000) / EWMA_DIV;
-
-	/* return standard deviation */
-	return (u16) int_sqrt(tmp_var);
+	return weight * (old_ewmv + MINSTREL_TRUNC(diff * incr)) / EWMA_DIV;
 }
 
 struct minstrel_rate_stats {
@@ -65,7 +60,7 @@ struct minstrel_rate_stats {
 	 *  prob_ewma - exponential weighted moving average of prob
 	 *  prob_ewmsd - exp. weighted moving standard deviation of prob */
 	unsigned int prob_ewma;
-	u16 prob_ewmsd;
+	u16 prob_ewmv;
 
 	/* maximum retry counts */
 	u8 retry_count;
@@ -151,6 +146,14 @@ struct minstrel_debugfs_info {
 	char buf[];
 };
 
+/* Get EWMSD (Exponentially Weighted Moving Standard Deviation) * 10 */
+static inline int
+minstrel_get_ewmsd10(struct minstrel_rate_stats *mrs)
+{
+	unsigned int ewmv = mrs->prob_ewmv;
+	return int_sqrt(MINSTREL_TRUNC(ewmv * 1000 * 1000));
+}
+
 extern const struct rate_control_ops mac80211_minstrel;
 void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
diff --git a/net/mac80211/rc80211_minstrel_debugfs.c b/net/mac80211/rc80211_minstrel_debugfs.c
index ca0bafd..36fc971 100644
--- a/net/mac80211/rc80211_minstrel_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_debugfs.c
@@ -93,6 +93,7 @@ minstrel_stats_open(struct inode *inode, struct file *file)
 	for (i = 0; i < mi->n_rates; i++) {
 		struct minstrel_rate *mr = &mi->r[i];
 		struct minstrel_rate_stats *mrs = &mi->r[i].stats;
+		unsigned int prob_ewmsd;
 
 		*(p++) = (i == mi->max_tp_rate[0]) ? 'A' : ' ';
 		*(p++) = (i == mi->max_tp_rate[1]) ? 'B' : ' ';
@@ -108,6 +109,7 @@ minstrel_stats_open(struct inode *inode, struct file *file)
 		tp_max = minstrel_get_tp_avg(mr, MINSTREL_FRAC(100,100));
 		tp_avg = minstrel_get_tp_avg(mr, mrs->prob_ewma);
 		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
+		prob_ewmsd = minstrel_get_ewmsd10(mrs);
 
 		p += sprintf(p, "%4u.%1u    %4u.%1u     %3u.%1u    %3u.%1u"
 				"     %3u   %3u %-3u   "
@@ -115,7 +117,7 @@ minstrel_stats_open(struct inode *inode, struct file *file)
 				tp_max / 10, tp_max % 10,
 				tp_avg / 10, tp_avg % 10,
 				eprob / 10, eprob % 10,
-				mrs->prob_ewmsd / 10, mrs->prob_ewmsd % 10,
+				prob_ewmsd / 10, prob_ewmsd % 10,
 				mrs->retry_count,
 				mrs->last_success,
 				mrs->last_attempts,
@@ -159,6 +161,7 @@ minstrel_stats_csv_open(struct inode *inode, struct file *file)
 	for (i = 0; i < mi->n_rates; i++) {
 		struct minstrel_rate *mr = &mi->r[i];
 		struct minstrel_rate_stats *mrs = &mi->r[i].stats;
+		unsigned int prob_ewmsd;
 
 		p += sprintf(p, "%s" ,((i == mi->max_tp_rate[0]) ? "A" : ""));
 		p += sprintf(p, "%s" ,((i == mi->max_tp_rate[1]) ? "B" : ""));
@@ -174,13 +177,14 @@ minstrel_stats_csv_open(struct inode *inode, struct file *file)
 		tp_max = minstrel_get_tp_avg(mr, MINSTREL_FRAC(100,100));
 		tp_avg = minstrel_get_tp_avg(mr, mrs->prob_ewma);
 		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
+		prob_ewmsd = minstrel_get_ewmsd10(mrs);
 
 		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u.%u,%u,%u,%u,"
 				"%llu,%llu,%d,%d\n",
 				tp_max / 10, tp_max % 10,
 				tp_avg / 10, tp_avg % 10,
 				eprob / 10, eprob % 10,
-				mrs->prob_ewmsd / 10, mrs->prob_ewmsd % 10,
+				prob_ewmsd / 10, prob_ewmsd % 10,
 				mrs->retry_count,
 				mrs->last_success,
 				mrs->last_attempts,
diff --git a/net/mac80211/rc80211_minstrel_ht_debugfs.c b/net/mac80211/rc80211_minstrel_ht_debugfs.c
index 0cecd23..7d969e3 100644
--- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
@@ -41,6 +41,7 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		struct minstrel_rate_stats *mrs = &mi->groups[i].rates[j];
 		static const int bitrates[4] = { 10, 20, 55, 110 };
 		int idx = i * MCS_GROUP_RATES + j;
+		unsigned int prob_ewmsd;
 
 		if (!(mi->supported[i] & BIT(j)))
 			continue;
@@ -84,6 +85,7 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
 		tp_avg = minstrel_ht_get_tp_avg(mi, i, j, mrs->prob_ewma);
 		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
+		prob_ewmsd = minstrel_get_ewmsd10(mrs);
 
 		p += sprintf(p, "%4u.%1u    %4u.%1u     %3u.%1u    %3u.%1u"
 				"     %3u   %3u %-3u   "
@@ -91,7 +93,7 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 				tp_max / 10, tp_max % 10,
 				tp_avg / 10, tp_avg % 10,
 				eprob / 10, eprob % 10,
-				mrs->prob_ewmsd / 10, mrs->prob_ewmsd % 10,
+				prob_ewmsd / 10, prob_ewmsd % 10,
 				mrs->retry_count,
 				mrs->last_success,
 				mrs->last_attempts,
@@ -185,6 +187,7 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		struct minstrel_rate_stats *mrs = &mi->groups[i].rates[j];
 		static const int bitrates[4] = { 10, 20, 55, 110 };
 		int idx = i * MCS_GROUP_RATES + j;
+		unsigned int prob_ewmsd;
 
 		if (!(mi->supported[i] & BIT(j)))
 			continue;
@@ -225,13 +228,14 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		tp_max = minstrel_ht_get_tp_avg(mi, i, j, MINSTREL_FRAC(100, 100));
 		tp_avg = minstrel_ht_get_tp_avg(mi, i, j, mrs->prob_ewma);
 		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
+		prob_ewmsd = minstrel_get_ewmsd10(mrs);
 
 		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u.%u,%u,%u,"
 				"%u,%llu,%llu,",
 				tp_max / 10, tp_max % 10,
 				tp_avg / 10, tp_avg % 10,
 				eprob / 10, eprob % 10,
-				mrs->prob_ewmsd / 10, mrs->prob_ewmsd % 10,
+				prob_ewmsd / 10, prob_ewmsd % 10,
 				mrs->retry_count,
 				mrs->last_success,
 				mrs->last_attempts,
-- 
2.10.1

[PATCH 08/10] mac80211: minstrel: make prob_ewma u16 instead of u32

[Felix Fietkau]

Saves about 1.2 KiB memory per station

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index ea86e67..be6c3f3 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -59,7 +59,7 @@ struct minstrel_rate_stats {
 	/* statistis of packet delivery probability
 	 *  prob_ewma - exponential weighted moving average of prob
 	 *  prob_ewmsd - exp. weighted moving standard deviation of prob */
-	unsigned int prob_ewma;
+	u16 prob_ewma;
 	u16 prob_ewmv;
 
 	/* maximum retry counts */
-- 
2.10.1

[PATCH 09/10] mac80211: minstrel_ht: remove obsolete #if for >= 3 streams

[Felix Fietkau]

This was added during early development when 3x3 hardware was not very
common yet. This is completely unnecessary now.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel_ht.c | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index ae45dcb..8e783e1 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -155,67 +155,47 @@ MODULE_PARM_DESC(minstrel_vht_only,
 const struct mcs_group minstrel_mcs_groups[] = {
 	MCS_GROUP(1, 0, BW_20),
 	MCS_GROUP(2, 0, BW_20),
-#if MINSTREL_MAX_STREAMS >= 3
 	MCS_GROUP(3, 0, BW_20),
-#endif
 
 	MCS_GROUP(1, 1, BW_20),
 	MCS_GROUP(2, 1, BW_20),
-#if MINSTREL_MAX_STREAMS >= 3
 	MCS_GROUP(3, 1, BW_20),
-#endif
 
 	MCS_GROUP(1, 0, BW_40),
 	MCS_GROUP(2, 0, BW_40),
-#if MINSTREL_MAX_STREAMS >= 3
 	MCS_GROUP(3, 0, BW_40),
-#endif
 
 	MCS_GROUP(1, 1, BW_40),
 	MCS_GROUP(2, 1, BW_40),
-#if MINSTREL_MAX_STREAMS >= 3
 	MCS_GROUP(3, 1, BW_40),
-#endif
 
 	CCK_GROUP,
 
 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
 	VHT_GROUP(1, 0, BW_20),
 	VHT_GROUP(2, 0, BW_20),
-#if MINSTREL_MAX_STREAMS >= 3
 	VHT_GROUP(3, 0, BW_20),
-#endif
 
 	VHT_GROUP(1, 1, BW_20),
 	VHT_GROUP(2, 1, BW_20),
-#if MINSTREL_MAX_STREAMS >= 3
 	VHT_GROUP(3, 1, BW_20),
-#endif
 
 	VHT_GROUP(1, 0, BW_40),
 	VHT_GROUP(2, 0, BW_40),
-#if MINSTREL_MAX_STREAMS >= 3
 	VHT_GROUP(3, 0, BW_40),
-#endif
 
 	VHT_GROUP(1, 1, BW_40),
 	VHT_GROUP(2, 1, BW_40),
-#if MINSTREL_MAX_STREAMS >= 3
 	VHT_GROUP(3, 1, BW_40),
-#endif
 
 	VHT_GROUP(1, 0, BW_80),
 	VHT_GROUP(2, 0, BW_80),
-#if MINSTREL_MAX_STREAMS >= 3
 	VHT_GROUP(3, 0, BW_80),
-#endif
 
 	VHT_GROUP(1, 1, BW_80),
 	VHT_GROUP(2, 1, BW_80),
-#if MINSTREL_MAX_STREAMS >= 3
 	VHT_GROUP(3, 1, BW_80),
 #endif
-#endif
 };
 
 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
-- 
2.10.1

[PATCH 10/10] mac80211: minstrel: avoid port control frames for sampling

[Felix Fietkau]

From: Thomas Huehn <thomas.huehn@evernet-eg.de>

Makes connections more reliable

Signed-off-by: Thomas Huehn <thomas.huehn@evernet-eg.de>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/rc80211_minstrel.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 11a4cc3..3ebe440 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -367,6 +367,11 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
 		return;
 #endif
 
+	/* Don't use EAPOL frames for sampling on non-mrr hw */
+	if (mp->hw->max_rates == 1 &&
+	    (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
+		return;
+
 	delta = (mi->total_packets * sampling_ratio / 100) -
 			(mi->sample_packets + mi->sample_deferred / 2);
 
-- 
2.10.1

Re: [PATCH 01/10] mac80211: minstrel_ht: move supported bitrate mask out of group data

[Johannes Berg]

That all looks good, applied.

johannes