From fe1818cdbc70331228506a543a9a6ac50cb90018 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Mon, 13 Jan 2020 19:38:55 +0100 Subject: mac80211: renumber subsys patches accepted upstream Signed-off-by: Felix Fietkau --- ...nstrel_ht-replace-rate-stats-ewma-with-a-.patch | 235 --------------------- 1 file changed, 235 deletions(-) delete mode 100644 package/kernel/mac80211/patches/subsys/361-mac80211-minstrel_ht-replace-rate-stats-ewma-with-a-.patch (limited to 'package/kernel/mac80211/patches/subsys/361-mac80211-minstrel_ht-replace-rate-stats-ewma-with-a-.patch') diff --git a/package/kernel/mac80211/patches/subsys/361-mac80211-minstrel_ht-replace-rate-stats-ewma-with-a-.patch b/package/kernel/mac80211/patches/subsys/361-mac80211-minstrel_ht-replace-rate-stats-ewma-with-a-.patch deleted file mode 100644 index bce9e75378..0000000000 --- a/package/kernel/mac80211/patches/subsys/361-mac80211-minstrel_ht-replace-rate-stats-ewma-with-a-.patch +++ /dev/null @@ -1,235 +0,0 @@ -From: Felix Fietkau -Date: Sat, 28 Sep 2019 15:46:06 +0200 -Subject: [PATCH] mac80211: minstrel_ht: replace rate stats ewma with a - better moving average - -Rate success probability usually fluctuates a lot under normal conditions. -With a simple EWMA, noise and fluctuation can be reduced by increasing the -window length, but that comes at the cost of introducing lag on sudden -changes. - -This change replaces the EWMA implementation with a moving average that's -designed to significantly reduce lag while keeping a bigger window size -by being better at filtering out noise. - -It is only slightly more expensive than the simple EWMA and still avoids -divisions in its calculation. - -The algorithm is adapted from an implementation intended for a completely -different field (stock market trading), where the tradeoff of lag vs -noise filtering is equally important. - -The algorithm works in the same way as the "smoothing filter" from -http://www.stockspotter.com/files/PredictiveIndicators.pdf adapted for -fixed-point math with some constants, using only addition, bit shifts -and multiplication - -To better make use of the filtering and bigger window size, the update -interval is cut in half. - -For testing, the algorithm can be reverted to the older one via debugfs - -Signed-off-by: Felix Fietkau ---- - ---- a/net/mac80211/rc80211_minstrel.c -+++ b/net/mac80211/rc80211_minstrel.c -@@ -157,14 +157,18 @@ minstrel_update_rates(struct minstrel_pr - * Recalculate statistics and counters of a given rate - */ - void --minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs) -+minstrel_calc_rate_stats(struct minstrel_priv *mp, -+ struct minstrel_rate_stats *mrs) - { - unsigned int cur_prob; - - if (unlikely(mrs->attempts > 0)) { - mrs->sample_skipped = 0; - cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); -- if (unlikely(!mrs->att_hist)) { -+ if (mp->new_avg) { -+ mrs->prob_ewma = minstrel_filter_avg_add(&mrs->avg, -+ cur_prob); -+ } else if (unlikely(!mrs->att_hist)) { - mrs->prob_ewma = cur_prob; - } else { - /*update exponential weighted moving avarage */ -@@ -200,7 +204,7 @@ minstrel_update_stats(struct minstrel_pr - struct minstrel_rate_stats *tmp_mrs = &mi->r[tmp_prob_rate].stats; - - /* Update statistics of success probability per rate */ -- minstrel_calc_rate_stats(mrs); -+ minstrel_calc_rate_stats(mp, mrs); - - /* Sample less often below the 10% chance of success. - * Sample less often above the 95% chance of success. */ -@@ -289,7 +293,8 @@ minstrel_tx_status(void *priv, struct ie - if (mi->sample_deferred > 0) - mi->sample_deferred--; - -- if (time_after(jiffies, mi->last_stats_update + mp->update_interval)) -+ if (time_after(jiffies, mi->last_stats_update + -+ mp->update_interval / (mp->new_avg ? 2 : 1))) - minstrel_update_stats(mp, mi); - } - ---- a/net/mac80211/rc80211_minstrel.h -+++ b/net/mac80211/rc80211_minstrel.h -@@ -19,6 +19,21 @@ - #define MAX_THR_RATES 4 - - /* -+ * Coefficients for moving average with noise filter (period=16), -+ * scaled by 10 bits -+ * -+ * a1 = exp(-pi * sqrt(2) / period) -+ * coeff2 = 2 * a1 * cos(sqrt(2) * 2 * pi / period) -+ * coeff3 = -sqr(a1) -+ * coeff1 = 1 - coeff2 - coeff3 -+ */ -+#define MINSTREL_AVG_COEFF1 (MINSTREL_FRAC(1, 1) - \ -+ MINSTREL_AVG_COEFF2 - \ -+ MINSTREL_AVG_COEFF3) -+#define MINSTREL_AVG_COEFF2 0x00001499 -+#define MINSTREL_AVG_COEFF3 -0x0000092e -+ -+/* - * Perform EWMA (Exponentially Weighted Moving Average) calculation - */ - static inline int -@@ -32,6 +47,41 @@ minstrel_ewma(int old, int new, int weig - return old + incr; - } - -+struct minstrel_avg_ctx { -+ s32 prev[2]; -+}; -+ -+static inline int minstrel_filter_avg_add(struct minstrel_avg_ctx *ctx, s32 in) -+{ -+ s32 out_1 = ctx->prev[0]; -+ s32 out_2 = ctx->prev[1]; -+ s32 val; -+ -+ if (!in) -+ in += 1; -+ -+ if (!out_1) { -+ val = out_1 = in; -+ goto out; -+ } -+ -+ val = MINSTREL_AVG_COEFF1 * in; -+ val += MINSTREL_AVG_COEFF2 * out_1; -+ val += MINSTREL_AVG_COEFF3 * out_2; -+ val >>= MINSTREL_SCALE; -+ -+ if (val > 1 << MINSTREL_SCALE) -+ val = 1 << MINSTREL_SCALE; -+ if (val < 0) -+ val = 1; -+ -+out: -+ ctx->prev[1] = out_1; -+ ctx->prev[0] = val; -+ -+ return val; -+} -+ - struct minstrel_rate_stats { - /* current / last sampling period attempts/success counters */ - u16 attempts, last_attempts; -@@ -40,6 +90,8 @@ struct minstrel_rate_stats { - /* total attempts/success counters */ - u32 att_hist, succ_hist; - -+ struct minstrel_avg_ctx avg; -+ - /* prob_ewma - exponential weighted moving average of prob */ - u16 prob_ewma; - -@@ -95,6 +147,7 @@ struct minstrel_sta_info { - struct minstrel_priv { - struct ieee80211_hw *hw; - bool has_mrr; -+ bool new_avg; - u32 sample_switch; - unsigned int cw_min; - unsigned int cw_max; -@@ -126,7 +179,8 @@ extern const struct rate_control_ops mac - void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir); - - /* Recalculate success probabilities and counters for a given rate using EWMA */ --void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs); -+void minstrel_calc_rate_stats(struct minstrel_priv *mp, -+ struct minstrel_rate_stats *mrs); - int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma); - - /* debugfs */ ---- a/net/mac80211/rc80211_minstrel_ht.c -+++ b/net/mac80211/rc80211_minstrel_ht.c -@@ -737,7 +737,7 @@ minstrel_ht_update_stats(struct minstrel - - mrs = &mg->rates[i]; - mrs->retry_updated = false; -- minstrel_calc_rate_stats(mrs); -+ minstrel_calc_rate_stats(mp, mrs); - cur_prob = mrs->prob_ewma; - - if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) -@@ -773,6 +773,8 @@ minstrel_ht_update_stats(struct minstrel - - /* try to sample all available rates during each interval */ - mi->sample_count *= 8; -+ if (mp->new_avg) -+ mi->sample_count /= 2; - - if (sample) - minstrel_ht_rate_sample_switch(mp, mi); -@@ -889,6 +891,7 @@ minstrel_ht_tx_status(void *priv, struct - struct ieee80211_tx_rate *ar = info->status.rates; - struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL; - struct minstrel_priv *mp = priv; -+ u32 update_interval = mp->update_interval / 2; - bool last, update = false; - bool sample_status = false; - int i; -@@ -943,6 +946,10 @@ minstrel_ht_tx_status(void *priv, struct - - switch (mi->sample_mode) { - case MINSTREL_SAMPLE_IDLE: -+ if (mp->new_avg && -+ (mp->hw->max_rates > 1 || -+ mi->total_packets_cur < SAMPLE_SWITCH_THR)) -+ update_interval /= 2; - break; - - case MINSTREL_SAMPLE_ACTIVE: -@@ -983,8 +990,7 @@ minstrel_ht_tx_status(void *priv, struct - } - } - -- if (time_after(jiffies, mi->last_stats_update + -- mp->update_interval / 2)) { -+ if (time_after(jiffies, mi->last_stats_update + update_interval)) { - update = true; - minstrel_ht_update_stats(mp, mi, true); - } -@@ -1665,6 +1671,7 @@ minstrel_ht_alloc(struct ieee80211_hw *h - - mp->hw = hw; - mp->update_interval = HZ / 10; -+ mp->new_avg = true; - - #ifdef CPTCFG_MAC80211_DEBUGFS - mp->fixed_rate_idx = (u32) -1; -@@ -1672,6 +1679,8 @@ minstrel_ht_alloc(struct ieee80211_hw *h - &mp->fixed_rate_idx); - debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir, - &mp->sample_switch); -+ debugfs_create_bool("new_avg", S_IRUGO | S_IWUSR, debugfsdir, -+ &mp->new_avg); - #endif - - minstrel_ht_init_cck_rates(mp); -- cgit v1.2.3