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path: root/net/mac80211/rc80211_minstrel.c
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Diffstat (limited to 'net/mac80211/rc80211_minstrel.c')
-rw-r--r--net/mac80211/rc80211_minstrel.c125
1 files changed, 85 insertions, 40 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index ef6e8a6c4253..247552a7f6c2 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -69,14 +69,39 @@ rix_to_ndx(struct minstrel_sta_info *mi, int rix)
return i;
}
+/* return current EMWA throughput */
+int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma)
+{
+ int usecs;
+
+ usecs = mr->perfect_tx_time;
+ if (!usecs)
+ usecs = 1000000;
+
+ /* reset thr. below 10% success */
+ if (mr->stats.prob_ewma < MINSTREL_FRAC(10, 100))
+ return 0;
+
+ if (prob_ewma > MINSTREL_FRAC(90, 100))
+ return MINSTREL_TRUNC(100000 * (MINSTREL_FRAC(90, 100) / usecs));
+ else
+ return MINSTREL_TRUNC(100000 * (prob_ewma / usecs));
+}
+
/* find & sort topmost throughput rates */
static inline void
minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list)
{
int j = MAX_THR_RATES;
+ struct minstrel_rate_stats *tmp_mrs = &mi->r[j - 1].stats;
+ struct minstrel_rate_stats *cur_mrs = &mi->r[i].stats;
- while (j > 0 && mi->r[i].stats.cur_tp > mi->r[tp_list[j - 1]].stats.cur_tp)
+ while (j > 0 && (minstrel_get_tp_avg(&mi->r[i], cur_mrs->prob_ewma) >
+ minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_ewma))) {
j--;
+ tmp_mrs = &mi->r[tp_list[j - 1]].stats;
+ }
+
if (j < MAX_THR_RATES - 1)
memmove(&tp_list[j + 1], &tp_list[j], MAX_THR_RATES - (j + 1));
if (j < MAX_THR_RATES)
@@ -127,13 +152,47 @@ minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
rate_control_set_rates(mp->hw, mi->sta, ratetbl);
}
+/*
+* Recalculate statistics and counters of a given rate
+*/
+void
+minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs)
+{
+ if (unlikely(mrs->attempts > 0)) {
+ mrs->sample_skipped = 0;
+ mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
+ if (unlikely(!mrs->att_hist)) {
+ mrs->prob_ewma = mrs->cur_prob;
+ } else {
+ /* update exponential weighted moving variance */
+ mrs->prob_ewmsd = minstrel_ewmsd(mrs->prob_ewmsd,
+ mrs->cur_prob,
+ mrs->prob_ewma,
+ EWMA_LEVEL);
+
+ /*update exponential weighted moving avarage */
+ mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma,
+ mrs->cur_prob,
+ EWMA_LEVEL);
+ }
+ mrs->att_hist += mrs->attempts;
+ mrs->succ_hist += mrs->success;
+ } else {
+ mrs->sample_skipped++;
+ }
+
+ mrs->last_success = mrs->success;
+ mrs->last_attempts = mrs->attempts;
+ mrs->success = 0;
+ mrs->attempts = 0;
+}
+
static void
minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
{
u8 tmp_tp_rate[MAX_THR_RATES];
u8 tmp_prob_rate = 0;
- u32 usecs;
- int i;
+ int i, tmp_cur_tp, tmp_prob_tp;
for (i = 0; i < MAX_THR_RATES; i++)
tmp_tp_rate[i] = 0;
@@ -141,38 +200,15 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
for (i = 0; i < mi->n_rates; i++) {
struct minstrel_rate *mr = &mi->r[i];
struct minstrel_rate_stats *mrs = &mi->r[i].stats;
+ struct minstrel_rate_stats *tmp_mrs = &mi->r[tmp_prob_rate].stats;
- usecs = mr->perfect_tx_time;
- if (!usecs)
- usecs = 1000000;
-
- if (unlikely(mrs->attempts > 0)) {
- mrs->sample_skipped = 0;
- mrs->cur_prob = MINSTREL_FRAC(mrs->success,
- mrs->attempts);
- mrs->succ_hist += mrs->success;
- mrs->att_hist += mrs->attempts;
- mrs->probability = minstrel_ewma(mrs->probability,
- mrs->cur_prob,
- EWMA_LEVEL);
- } else
- mrs->sample_skipped++;
-
- mrs->last_success = mrs->success;
- mrs->last_attempts = mrs->attempts;
- mrs->success = 0;
- mrs->attempts = 0;
-
- /* Update throughput per rate, reset thr. below 10% success */
- if (mrs->probability < MINSTREL_FRAC(10, 100))
- mrs->cur_tp = 0;
- else
- mrs->cur_tp = mrs->probability * (1000000 / usecs);
+ /* Update statistics of success probability per rate */
+ minstrel_calc_rate_stats(mrs);
/* Sample less often below the 10% chance of success.
* Sample less often above the 95% chance of success. */
- if (mrs->probability > MINSTREL_FRAC(95, 100) ||
- mrs->probability < MINSTREL_FRAC(10, 100)) {
+ if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
+ mrs->prob_ewma < MINSTREL_FRAC(10, 100)) {
mr->adjusted_retry_count = mrs->retry_count >> 1;
if (mr->adjusted_retry_count > 2)
mr->adjusted_retry_count = 2;
@@ -192,11 +228,14 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
* choose the maximum throughput rate as max_prob_rate
* (2) if all success probabilities < 95%, the rate with
* highest success probability is chosen as max_prob_rate */
- if (mrs->probability >= MINSTREL_FRAC(95, 100)) {
- if (mrs->cur_tp >= mi->r[tmp_prob_rate].stats.cur_tp)
+ if (mrs->prob_ewma >= MINSTREL_FRAC(95, 100)) {
+ tmp_cur_tp = minstrel_get_tp_avg(mr, mrs->prob_ewma);
+ tmp_prob_tp = minstrel_get_tp_avg(&mi->r[tmp_prob_rate],
+ tmp_mrs->prob_ewma);
+ if (tmp_cur_tp >= tmp_prob_tp)
tmp_prob_rate = i;
} else {
- if (mrs->probability >= mi->r[tmp_prob_rate].stats.probability)
+ if (mrs->prob_ewma >= tmp_mrs->prob_ewma)
tmp_prob_rate = i;
}
}
@@ -215,7 +254,7 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
#endif
/* Reset update timer */
- mi->stats_update = jiffies;
+ mi->last_stats_update = jiffies;
minstrel_update_rates(mp, mi);
}
@@ -253,7 +292,7 @@ minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband,
if (mi->sample_deferred > 0)
mi->sample_deferred--;
- if (time_after(jiffies, mi->stats_update +
+ if (time_after(jiffies, mi->last_stats_update +
(mp->update_interval * HZ) / 1000))
minstrel_update_stats(mp, mi);
}
@@ -385,7 +424,7 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
* has a probability of >95%, we shouldn't be attempting
* to use it, as this only wastes precious airtime */
if (!mrr_capable &&
- (mi->r[ndx].stats.probability > MINSTREL_FRAC(95, 100)))
+ (mi->r[ndx].stats.prob_ewma > MINSTREL_FRAC(95, 100)))
return;
mi->prev_sample = true;
@@ -519,7 +558,7 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
}
mi->n_rates = n;
- mi->stats_update = jiffies;
+ mi->last_stats_update = jiffies;
init_sample_table(mi);
minstrel_update_rates(mp, mi);
@@ -553,7 +592,7 @@ minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
if (!mi->sample_table)
goto error1;
- mi->stats_update = jiffies;
+ mi->last_stats_update = jiffies;
return mi;
error1:
@@ -663,12 +702,18 @@ minstrel_free(void *priv)
static u32 minstrel_get_expected_throughput(void *priv_sta)
{
struct minstrel_sta_info *mi = priv_sta;
+ struct minstrel_rate_stats *tmp_mrs;
int idx = mi->max_tp_rate[0];
+ int tmp_cur_tp;
/* convert pkt per sec in kbps (1200 is the average pkt size used for
* computing cur_tp
*/
- return MINSTREL_TRUNC(mi->r[idx].stats.cur_tp) * 1200 * 8 / 1024;
+ tmp_mrs = &mi->r[idx].stats;
+ tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma);
+ tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024;
+
+ return tmp_cur_tp;
}
const struct rate_control_ops mac80211_minstrel = {