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-rw-r--r--package/kernel/mac80211/patches/340-mac80211-minstrel-store-probability-variance-instead.patch186
1 files changed, 186 insertions, 0 deletions
diff --git a/package/kernel/mac80211/patches/340-mac80211-minstrel-store-probability-variance-instead.patch b/package/kernel/mac80211/patches/340-mac80211-minstrel-store-probability-variance-instead.patch
new file mode 100644
index 0000000000..f679a43224
--- /dev/null
+++ b/package/kernel/mac80211/patches/340-mac80211-minstrel-store-probability-variance-instead.patch
@@ -0,0 +1,186 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Wed, 14 Dec 2016 20:17:06 +0100
+Subject: [PATCH] mac80211: minstrel: store probability variance instead of
+ standard deviation
+
+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>
+---
+
+--- a/net/mac80211/rc80211_minstrel.c
++++ b/net/mac80211/rc80211_minstrel.c
+@@ -168,10 +168,10 @@ minstrel_calc_rate_stats(struct minstrel
+ 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,
+--- a/net/mac80211/rc80211_minstrel.h
++++ b/net/mac80211/rc80211_minstrel.h
+@@ -36,21 +36,16 @@ minstrel_ewma(int old, int new, int weig
+ }
+
+ /*
+- * 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);
+--- a/net/mac80211/rc80211_minstrel_debugfs.c
++++ b/net/mac80211/rc80211_minstrel_debugfs.c
+@@ -93,6 +93,7 @@ minstrel_stats_open(struct inode *inode,
+ 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,
+ 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,
+ 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 *in
+ 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 *in
+ 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,
+--- 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_h
+ 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_h
+ 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_h
+ 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 minstr
+ 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 minstr
+ 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,
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-08 01:36:23 +0000