mac80211: add AQL improvements

Add AQL support for HE drivers.
Improve assumed aggregation length based on tx rate

Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2020-08-12 17:12:03 +02:00
parent 6bee8f2865
commit 431fb8cae9
3 changed files with 403 additions and 0 deletions

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@ -0,0 +1,151 @@
From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 12 Aug 2020 17:04:22 +0200
Subject: [PATCH] mac80211: use rate provided via status->rate on
ieee80211_tx_status_ext for AQL
Since ieee80211_tx_info does not have enough room to encode HE rates, HE
drivers use status->rate to provide rate info.
Store it in struct sta_info and use it for AQL.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/net/mac80211/airtime.c
+++ b/net/mac80211/airtime.c
@@ -487,14 +487,61 @@ u32 ieee80211_calc_rx_airtime(struct iee
}
EXPORT_SYMBOL_GPL(ieee80211_calc_rx_airtime);
+static bool ieee80211_fill_rate_info(struct ieee80211_hw *hw,
+ struct ieee80211_rx_status *stat, u8 band,
+ struct rate_info *ri)
+{
+ struct ieee80211_supported_band *sband = hw->wiphy->bands[band];
+ int i;
+
+ if (!ri || !sband)
+ return false;
+
+ stat->bw = ri->bw;
+ stat->nss = ri->nss;
+ stat->rate_idx = ri->mcs;
+
+ if (ri->flags & RATE_INFO_FLAGS_HE_MCS)
+ stat->encoding = RX_ENC_HE;
+ else if (ri->flags & RATE_INFO_FLAGS_VHT_MCS)
+ stat->encoding = RX_ENC_VHT;
+ else if (ri->flags & RATE_INFO_FLAGS_MCS)
+ stat->encoding = RX_ENC_HT;
+ else
+ stat->encoding = RX_ENC_LEGACY;
+
+ if (ri->flags & RATE_INFO_FLAGS_SHORT_GI)
+ stat->enc_flags |= RX_ENC_FLAG_SHORT_GI;
+
+ stat->he_gi = ri->he_gi;
+
+ if (stat->encoding != RX_ENC_LEGACY)
+ return true;
+
+ stat->rate_idx = 0;
+ for (i = 0; i < sband->n_bitrates; i++) {
+ if (ri->legacy != sband->bitrates[i].bitrate)
+ continue;
+
+ stat->rate_idx = i;
+ return true;
+ }
+
+ return false;
+}
+
static u32 ieee80211_calc_tx_airtime_rate(struct ieee80211_hw *hw,
struct ieee80211_tx_rate *rate,
+ struct rate_info *ri,
u8 band, int len)
{
struct ieee80211_rx_status stat = {
.band = band,
};
+ if (ieee80211_fill_rate_info(hw, &stat, band, ri))
+ goto out;
+
if (rate->idx < 0 || !rate->count)
return 0;
@@ -522,6 +569,7 @@ static u32 ieee80211_calc_tx_airtime_rat
stat.encoding = RX_ENC_LEGACY;
}
+out:
return ieee80211_calc_rx_airtime(hw, &stat, len);
}
@@ -536,7 +584,7 @@ u32 ieee80211_calc_tx_airtime(struct iee
struct ieee80211_tx_rate *rate = &info->status.rates[i];
u32 cur_duration;
- cur_duration = ieee80211_calc_tx_airtime_rate(hw, rate,
+ cur_duration = ieee80211_calc_tx_airtime_rate(hw, rate, NULL,
info->band, len);
if (!cur_duration)
break;
@@ -573,6 +621,7 @@ u32 ieee80211_calc_expected_tx_airtime(s
struct sta_info *sta = container_of(pubsta, struct sta_info,
sta);
struct ieee80211_tx_rate *rate = &sta->tx_stats.last_rate;
+ struct rate_info *ri = &sta->tx_stats.last_rate_info;
u32 airtime;
if (!(rate->flags & (IEEE80211_TX_RC_VHT_MCS |
@@ -586,7 +635,7 @@ u32 ieee80211_calc_expected_tx_airtime(s
* This will not be very accurate, but much better than simply
* assuming un-aggregated tx.
*/
- airtime = ieee80211_calc_tx_airtime_rate(hw, rate, band,
+ airtime = ieee80211_calc_tx_airtime_rate(hw, rate, ri, band,
ampdu ? len * 16 : len);
if (ampdu)
airtime /= 16;
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -609,6 +609,7 @@ struct sta_info {
u64 packets[IEEE80211_NUM_ACS];
u64 bytes[IEEE80211_NUM_ACS];
struct ieee80211_tx_rate last_rate;
+ struct rate_info last_rate_info;
u64 msdu[IEEE80211_NUM_TIDS + 1];
} tx_stats;
u16 tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1];
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -1147,9 +1147,17 @@ void ieee80211_tx_status_ext(struct ieee
struct ieee80211_tx_info *info = status->info;
struct ieee80211_sta *pubsta = status->sta;
struct ieee80211_supported_band *sband;
+ struct sta_info *sta;
int retry_count;
bool acked, noack_success;
+ if (pubsta) {
+ sta = container_of(pubsta, struct sta_info, sta);
+
+ if (status->rate)
+ sta->tx_stats.last_rate_info = *status->rate;
+ }
+
if (status->skb)
return __ieee80211_tx_status(hw, status);
@@ -1164,10 +1172,6 @@ void ieee80211_tx_status_ext(struct ieee
noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
if (pubsta) {
- struct sta_info *sta;
-
- sta = container_of(pubsta, struct sta_info, sta);
-
if (!acked && !noack_success)
sta->status_stats.retry_failed++;
sta->status_stats.retry_count += retry_count;

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@ -0,0 +1,186 @@
From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 12 Aug 2020 17:06:12 +0200
Subject: [PATCH] mac80211: factor out code to look up the average packet
length duration for a rate
This will be used to enhance AQL estimated aggregation length
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/net/mac80211/airtime.c
+++ b/net/mac80211/airtime.c
@@ -405,18 +405,14 @@ ieee80211_calc_legacy_rate_duration(u16
return duration;
}
-u32 ieee80211_calc_rx_airtime(struct ieee80211_hw *hw,
- struct ieee80211_rx_status *status,
- int len)
+static u32 ieee80211_get_rate_duration(struct ieee80211_hw *hw,
+ struct ieee80211_rx_status *status,
+ u32 *overhead)
{
- struct ieee80211_supported_band *sband;
- const struct ieee80211_rate *rate;
bool sgi = status->enc_flags & RX_ENC_FLAG_SHORT_GI;
- bool sp = status->enc_flags & RX_ENC_FLAG_SHORTPRE;
int bw, streams;
int group, idx;
u32 duration;
- bool cck;
switch (status->bw) {
case RATE_INFO_BW_20:
@@ -437,20 +433,6 @@ u32 ieee80211_calc_rx_airtime(struct iee
}
switch (status->encoding) {
- case RX_ENC_LEGACY:
- if (WARN_ON_ONCE(status->band > NL80211_BAND_5GHZ))
- return 0;
-
- sband = hw->wiphy->bands[status->band];
- if (!sband || status->rate_idx >= sband->n_bitrates)
- return 0;
-
- rate = &sband->bitrates[status->rate_idx];
- cck = rate->flags & IEEE80211_RATE_MANDATORY_B;
-
- return ieee80211_calc_legacy_rate_duration(rate->bitrate, sp,
- cck, len);
-
case RX_ENC_VHT:
streams = status->nss;
idx = status->rate_idx;
@@ -477,13 +459,47 @@ u32 ieee80211_calc_rx_airtime(struct iee
duration = airtime_mcs_groups[group].duration[idx];
duration <<= airtime_mcs_groups[group].shift;
+ *overhead = 36 + (streams << 2);
+
+ return duration;
+}
+
+
+u32 ieee80211_calc_rx_airtime(struct ieee80211_hw *hw,
+ struct ieee80211_rx_status *status,
+ int len)
+{
+ struct ieee80211_supported_band *sband;
+ u32 duration, overhead = 0;
+
+ if (status->encoding == RX_ENC_LEGACY) {
+ const struct ieee80211_rate *rate;
+ bool sp = status->enc_flags & RX_ENC_FLAG_SHORTPRE;
+ bool cck;
+
+ if (WARN_ON_ONCE(status->band > NL80211_BAND_5GHZ))
+ return 0;
+
+ sband = hw->wiphy->bands[status->band];
+ if (!sband || status->rate_idx >= sband->n_bitrates)
+ return 0;
+
+ rate = &sband->bitrates[status->rate_idx];
+ cck = rate->flags & IEEE80211_RATE_MANDATORY_B;
+
+ return ieee80211_calc_legacy_rate_duration(rate->bitrate, sp,
+ cck, len);
+ }
+
+ duration = ieee80211_get_rate_duration(hw, status, &overhead);
+ if (!duration)
+ return 0;
+
duration *= len;
duration /= AVG_PKT_SIZE;
duration /= 1024;
- duration += 36 + (streams << 2);
-
- return duration;
+ return duration + overhead;
}
EXPORT_SYMBOL_GPL(ieee80211_calc_rx_airtime);
@@ -530,46 +546,56 @@ static bool ieee80211_fill_rate_info(str
return false;
}
-static u32 ieee80211_calc_tx_airtime_rate(struct ieee80211_hw *hw,
- struct ieee80211_tx_rate *rate,
- struct rate_info *ri,
- u8 band, int len)
+static int ieee80211_fill_rx_status(struct ieee80211_rx_status *stat,
+ struct ieee80211_hw *hw,
+ struct ieee80211_tx_rate *rate,
+ struct rate_info *ri, u8 band, int len)
{
- struct ieee80211_rx_status stat = {
- .band = band,
- };
+ memset(stat, 0, sizeof(*stat));
+ stat->band = band;
- if (ieee80211_fill_rate_info(hw, &stat, band, ri))
- goto out;
+ if (ieee80211_fill_rate_info(hw, stat, band, ri))
+ return 0;
if (rate->idx < 0 || !rate->count)
- return 0;
+ return -1;
if (rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
- stat.bw = RATE_INFO_BW_80;
+ stat->bw = RATE_INFO_BW_80;
else if (rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
- stat.bw = RATE_INFO_BW_40;
+ stat->bw = RATE_INFO_BW_40;
else
- stat.bw = RATE_INFO_BW_20;
+ stat->bw = RATE_INFO_BW_20;
- stat.enc_flags = 0;
+ stat->enc_flags = 0;
if (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
- stat.enc_flags |= RX_ENC_FLAG_SHORTPRE;
+ stat->enc_flags |= RX_ENC_FLAG_SHORTPRE;
if (rate->flags & IEEE80211_TX_RC_SHORT_GI)
- stat.enc_flags |= RX_ENC_FLAG_SHORT_GI;
+ stat->enc_flags |= RX_ENC_FLAG_SHORT_GI;
- stat.rate_idx = rate->idx;
+ stat->rate_idx = rate->idx;
if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
- stat.encoding = RX_ENC_VHT;
- stat.rate_idx = ieee80211_rate_get_vht_mcs(rate);
- stat.nss = ieee80211_rate_get_vht_nss(rate);
+ stat->encoding = RX_ENC_VHT;
+ stat->rate_idx = ieee80211_rate_get_vht_mcs(rate);
+ stat->nss = ieee80211_rate_get_vht_nss(rate);
} else if (rate->flags & IEEE80211_TX_RC_MCS) {
- stat.encoding = RX_ENC_HT;
+ stat->encoding = RX_ENC_HT;
} else {
- stat.encoding = RX_ENC_LEGACY;
+ stat->encoding = RX_ENC_LEGACY;
}
-out:
+ return 0;
+}
+
+static u32 ieee80211_calc_tx_airtime_rate(struct ieee80211_hw *hw,
+ struct ieee80211_tx_rate *rate,
+ struct rate_info *ri,
+ u8 band, int len)
+{
+ struct ieee80211_rx_status stat;
+
+ ieee80211_fill_rx_status(&stat, hw, rate, ri, band, len);
+
return ieee80211_calc_rx_airtime(hw, &stat, len);
}

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@ -0,0 +1,66 @@
From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 12 Aug 2020 17:07:10 +0200
Subject: [PATCH] mac80211: improve AQL aggregation estimation for low data
rates
Links with low data rates use much smaller aggregates and are much more
sensitive to latency added by bufferbloat.
Tune the assumed aggregation length based on the tx rate duration.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/net/mac80211/airtime.c
+++ b/net/mac80211/airtime.c
@@ -646,27 +646,40 @@ u32 ieee80211_calc_expected_tx_airtime(s
if (pubsta) {
struct sta_info *sta = container_of(pubsta, struct sta_info,
sta);
+ struct ieee80211_rx_status stat;
struct ieee80211_tx_rate *rate = &sta->tx_stats.last_rate;
struct rate_info *ri = &sta->tx_stats.last_rate_info;
- u32 airtime;
+ u32 duration, overhead;
+ u8 agg_shift;
- if (!(rate->flags & (IEEE80211_TX_RC_VHT_MCS |
- IEEE80211_TX_RC_MCS)))
- ampdu = false;
+ ieee80211_fill_rx_status(&stat, hw, rate, ri, band, len);
+
+ if (stat.encoding == RX_ENC_LEGACY || !ampdu)
+ return ieee80211_calc_rx_airtime(hw, &stat, len);
+ duration = ieee80211_get_rate_duration(hw, &stat, &overhead);
/*
* Assume that HT/VHT transmission on any AC except VO will
* use aggregation. Since we don't have reliable reporting
- * of aggregation length, assume an average of 16.
+ * of aggregation length, assume an average size based on the
+ * tx rate.
* This will not be very accurate, but much better than simply
- * assuming un-aggregated tx.
+ * assuming un-aggregated tx in all cases.
*/
- airtime = ieee80211_calc_tx_airtime_rate(hw, rate, ri, band,
- ampdu ? len * 16 : len);
- if (ampdu)
- airtime /= 16;
+ if (duration > 400) /* <= VHT20 MCS2 1S */
+ agg_shift = 1;
+ else if (duration > 250) /* <= VHT20 MCS3 1S or MCS1 2S */
+ agg_shift = 2;
+ else if (duration > 150) /* <= VHT20 MCS5 1S or MCS3 2S */
+ agg_shift = 3;
+ else
+ agg_shift = 4;
- return airtime;
+ duration *= len;
+ duration /= AVG_PKT_SIZE;
+ duration /= 1024;
+
+ return duration + (overhead >> agg_shift);
}
if (!conf)