diff options
Diffstat (limited to 'net/mac80211/rc80211_minstrel_ht.c')
| -rw-r--r-- | net/mac80211/rc80211_minstrel_ht.c | 240 |
1 files changed, 212 insertions, 28 deletions
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index c5868a1de306..a01168514840 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -18,6 +18,8 @@ #define AVG_AMPDU_SIZE 16 #define AVG_PKT_SIZE 1200 +#define SAMPLE_SWITCH_THR 100 + /* Number of bits for an average sized packet */ #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3) @@ -58,6 +60,7 @@ [GROUP_IDX(_streams, _sgi, _ht40)] = { \ .streams = _streams, \ .shift = _s, \ + .bw = _ht40, \ .flags = \ IEEE80211_TX_RC_MCS | \ (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ @@ -94,6 +97,7 @@ [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ .streams = _streams, \ .shift = _s, \ + .bw = _bw, \ .flags = \ IEEE80211_TX_RC_VHT_MCS | \ (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ @@ -526,6 +530,133 @@ minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) } } +static inline int +minstrel_get_duration(int index) +{ + const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; + unsigned int duration = group->duration[index % MCS_GROUP_RATES]; + return duration << group->shift; +} + +static bool +minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group, + int tp_idx, const struct mcs_group *group) +{ + if (group->bw < tp_group->bw) + return false; + + if (group->streams == tp_group->streams) + return true; + + if (tp_idx < 4 && group->streams == tp_group->streams - 1) + return true; + + return group->streams == tp_group->streams + 1; +} + +static void +minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates, + bool faster_rate) +{ + const struct mcs_group *group, *tp_group; + int i, g, max_dur; + int tp_idx; + + tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES]; + tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES; + + max_dur = minstrel_get_duration(mi->max_tp_rate[0]); + if (faster_rate) + max_dur -= max_dur / 16; + + for (g = 0; g < MINSTREL_GROUPS_NB; g++) { + u16 supported = mi->supported[g]; + + if (!supported) + continue; + + group = &minstrel_mcs_groups[g]; + if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group)) + continue; + + for (i = 0; supported; supported >>= 1, i++) { + int idx; + + if (!(supported & 1)) + continue; + + if ((group->duration[i] << group->shift) > max_dur) + continue; + + idx = g * MCS_GROUP_RATES + i; + if (idx == mi->max_tp_rate[0]) + continue; + + rates[(*n_rates)++] = idx; + break; + } + } +} + +static void +minstrel_ht_rate_sample_switch(struct minstrel_priv *mp, + struct minstrel_ht_sta *mi) +{ + struct minstrel_rate_stats *mrs; + u16 rates[MINSTREL_GROUPS_NB]; + int n_rates = 0; + int probe_rate = 0; + bool faster_rate; + int i; + u8 random; + + /* + * Use rate switching instead of probing packets for devices with + * little control over retry fallback behavior + */ + if (mp->hw->max_rates > 1) + return; + + /* + * If the current EWMA prob is >75%, look for a rate that's 6.25% + * faster than the max tp rate. + * If that fails, look again for a rate that is at least as fast + */ + mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); + faster_rate = mrs->prob_ewma > MINSTREL_FRAC(75, 100); + minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate); + if (!n_rates && faster_rate) + minstrel_ht_find_probe_rates(mi, rates, &n_rates, false); + + /* If no suitable rate was found, try to pick the next one in the group */ + if (!n_rates) { + int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES; + u16 supported = mi->supported[g_idx]; + + supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES; + for (i = 0; supported; i++) { + if (!(supported & 1)) + continue; + + probe_rate = mi->max_tp_rate[0] + i; + goto out; + } + + return; + } + + i = 0; + if (n_rates > 1) { + random = prandom_u32(); + i = random % n_rates; + } + probe_rate = rates[i]; + +out: + mi->sample_rate = probe_rate; + mi->sample_mode = MINSTREL_SAMPLE_ACTIVE; +} + /* * Update rate statistics and select new primary rates * @@ -536,7 +667,8 @@ minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) * higher throughput rates, even if the probablity is a bit lower */ static void -minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) +minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, + bool sample) { struct minstrel_mcs_group_data *mg; struct minstrel_rate_stats *mrs; @@ -544,6 +676,18 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; u16 tmp_cck_tp_rate[MAX_THR_RATES], index; + mi->sample_mode = MINSTREL_SAMPLE_IDLE; + + if (sample) { + mi->total_packets_cur = mi->total_packets - + mi->total_packets_last; + mi->total_packets_last = mi->total_packets; + } + if (!mp->sample_switch) + sample = false; + if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1) + sample = false; + if (mi->ampdu_packets > 0) { if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN)) mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, @@ -630,12 +774,16 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) /* try to sample all available rates during each interval */ mi->sample_count *= 8; + if (sample) + minstrel_ht_rate_sample_switch(mp, mi); + #ifdef CONFIG_MAC80211_DEBUGFS /* use fixed index if set */ if (mp->fixed_rate_idx != -1) { for (i = 0; i < 4; i++) mi->max_tp_rate[i] = mp->fixed_rate_idx; mi->max_prob_rate = mp->fixed_rate_idx; + mi->sample_mode = MINSTREL_SAMPLE_IDLE; } #endif @@ -739,15 +887,17 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, struct minstrel_ht_sta_priv *msp = priv_sta; struct minstrel_ht_sta *mi = &msp->ht; struct ieee80211_tx_rate *ar = info->status.rates; - struct minstrel_rate_stats *rate, *rate2; + struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL; struct minstrel_priv *mp = priv; bool last, update = false; + bool sample_status = false; int i; if (!msp->is_ht) return mac80211_minstrel.tx_status_ext(priv, sband, &msp->legacy, st); + /* This packet was aggregated but doesn't carry status info */ if ((info->flags & IEEE80211_TX_CTL_AMPDU) && !(info->flags & IEEE80211_TX_STAT_AMPDU)) @@ -773,12 +923,17 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) mi->sample_packets += info->status.ampdu_len; + if (mi->sample_mode != MINSTREL_SAMPLE_IDLE) + rate_sample = minstrel_get_ratestats(mi, mi->sample_rate); + last = !minstrel_ht_txstat_valid(mp, &ar[0]); for (i = 0; !last; i++) { last = (i == IEEE80211_TX_MAX_RATES - 1) || !minstrel_ht_txstat_valid(mp, &ar[i + 1]); rate = minstrel_ht_get_stats(mp, mi, &ar[i]); + if (rate == rate_sample) + sample_status = true; if (last) rate->success += info->status.ampdu_ack_len; @@ -786,44 +941,60 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, rate->attempts += ar[i].count * info->status.ampdu_len; } - /* - * check for sudden death of spatial multiplexing, - * downgrade to a lower number of streams if necessary. - */ - rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); - if (rate->attempts > 30 && - MINSTREL_FRAC(rate->success, rate->attempts) < - MINSTREL_FRAC(20, 100)) { - minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); + switch (mi->sample_mode) { + case MINSTREL_SAMPLE_IDLE: + break; + + case MINSTREL_SAMPLE_ACTIVE: + if (!sample_status) + break; + + mi->sample_mode = MINSTREL_SAMPLE_PENDING; update = true; - } + break; + + case MINSTREL_SAMPLE_PENDING: + if (sample_status) + break; - rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); - if (rate2->attempts > 30 && - MINSTREL_FRAC(rate2->success, rate2->attempts) < - MINSTREL_FRAC(20, 100)) { - minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); update = true; + minstrel_ht_update_stats(mp, mi, false); + break; + } + + + if (mp->hw->max_rates > 1) { + /* + * check for sudden death of spatial multiplexing, + * downgrade to a lower number of streams if necessary. + */ + rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); + if (rate->attempts > 30 && + MINSTREL_FRAC(rate->success, rate->attempts) < + MINSTREL_FRAC(20, 100)) { + minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); + update = true; + } + + rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); + if (rate2->attempts > 30 && + MINSTREL_FRAC(rate2->success, rate2->attempts) < + MINSTREL_FRAC(20, 100)) { + minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); + update = true; + } } if (time_after(jiffies, mi->last_stats_update + (mp->update_interval / 2 * HZ) / 1000)) { update = true; - minstrel_ht_update_stats(mp, mi); + minstrel_ht_update_stats(mp, mi, true); } if (update) minstrel_ht_update_rates(mp, mi); } -static inline int -minstrel_get_duration(int index) -{ - const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; - unsigned int duration = group->duration[index % MCS_GROUP_RATES]; - return duration << group->shift; -} - static void minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, int index) @@ -988,14 +1159,18 @@ static void minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) { struct ieee80211_sta_rates *rates; + u16 first_rate = mi->max_tp_rate[0]; int i = 0; + if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE) + first_rate = mi->sample_rate; + rates = kzalloc(sizeof(*rates), GFP_ATOMIC); if (!rates) return; /* Start with max_tp_rate[0] */ - minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); + minstrel_ht_set_rate(mp, mi, rates, i++, first_rate); if (mp->hw->max_rates >= 3) { /* At least 3 tx rates supported, use max_tp_rate[1] next */ @@ -1020,6 +1195,11 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) int tp_rate1, tp_rate2; int sample_idx = 0; + if (mp->hw->max_rates == 1 && mp->sample_switch && + (mi->total_packets_cur >= SAMPLE_SWITCH_THR || + mp->sample_switch == 1)) + return -1; + if (mi->sample_wait > 0) { mi->sample_wait--; return -1; @@ -1341,7 +1521,7 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4; /* create an initial rate table with the lowest supported rates */ - minstrel_ht_update_stats(mp, mi); + minstrel_ht_update_stats(mp, mi, true); minstrel_ht_update_rates(mp, mi); return; @@ -1459,6 +1639,8 @@ minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) if (!mp) return NULL; + mp->sample_switch = -1; + /* contention window settings * Just an approximation. Using the per-queue values would complicate * the calculations and is probably unnecessary */ @@ -1490,6 +1672,8 @@ minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) mp->fixed_rate_idx = (u32) -1; debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); + debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir, + &mp->sample_switch); #endif minstrel_ht_init_cck_rates(mp); |