mac80211: add AQL improvements
authorFelix Fietkau <nbd@nbd.name>
Wed, 12 Aug 2020 15:12:03 +0000 (17:12 +0200)
committerFelix Fietkau <nbd@nbd.name>
Thu, 13 Aug 2020 15:57:19 +0000 (17:57 +0200)
Add AQL support for HE drivers.
Improve assumed aggregation length based on tx rate

Signed-off-by: Felix Fietkau <nbd@nbd.name>
package/kernel/mac80211/patches/subsys/311-mac80211-use-rate-provided-via-status-rate-on-ieee80.patch [new file with mode: 0644]
package/kernel/mac80211/patches/subsys/312-mac80211-factor-out-code-to-look-up-the-average-pack.patch [new file with mode: 0644]
package/kernel/mac80211/patches/subsys/313-mac80211-improve-AQL-aggregation-estimation-for-low-.patch [new file with mode: 0644]

diff --git a/package/kernel/mac80211/patches/subsys/311-mac80211-use-rate-provided-via-status-rate-on-ieee80.patch b/package/kernel/mac80211/patches/subsys/311-mac80211-use-rate-provided-via-status-rate-on-ieee80.patch
new file mode 100644 (file)
index 0000000..ee1db71
--- /dev/null
@@ -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;
diff --git a/package/kernel/mac80211/patches/subsys/312-mac80211-factor-out-code-to-look-up-the-average-pack.patch b/package/kernel/mac80211/patches/subsys/312-mac80211-factor-out-code-to-look-up-the-average-pack.patch
new file mode 100644 (file)
index 0000000..105bbe2
--- /dev/null
@@ -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);
+ }
diff --git a/package/kernel/mac80211/patches/subsys/313-mac80211-improve-AQL-aggregation-estimation-for-low-.patch b/package/kernel/mac80211/patches/subsys/313-mac80211-improve-AQL-aggregation-estimation-for-low-.patch
new file mode 100644 (file)
index 0000000..565d9be
--- /dev/null
@@ -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)