mac80211: add max lossless throughput per rate
This patch adds the new statistic "maximum possible lossless
throughput" to Minstrels and Minstrel-HTs rc_stats (in debugfs). This
enables comprehensive comparison between current per-rate throughput
and max. achievable per-rate throughput.
Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 7202e34..7430a1d 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -318,33 +318,30 @@
* account the expected number of retransmissions and their expected length
*/
int
-minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate)
+minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
+ int prob_ewma)
{
- struct minstrel_rate_stats *mrs;
unsigned int nsecs = 0;
- unsigned int tmp_prob_ewma;
-
- mrs = &mi->groups[group].rates[rate];
- tmp_prob_ewma = mrs->prob_ewma;
/* do not account throughput if sucess prob is below 10% */
- if (mrs->prob_ewma < MINSTREL_FRAC(10, 100))
+ if (prob_ewma < MINSTREL_FRAC(10, 100))
return 0;
- /*
- * For the throughput calculation, limit the probability value to 90% to
- * account for collision related packet error rate fluctuation
- */
- if (mrs->prob_ewma > MINSTREL_FRAC(90, 100))
- tmp_prob_ewma = MINSTREL_FRAC(90, 100);
-
if (group != MINSTREL_CCK_GROUP)
nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
nsecs += minstrel_mcs_groups[group].duration[rate];
- /* prob is scaled - see MINSTREL_FRAC above */
- return MINSTREL_TRUNC(100000 * ((tmp_prob_ewma * 1000) / nsecs));
+ /*
+ * For the throughput calculation, limit the probability value to 90% to
+ * account for collision related packet error rate fluctuation
+ * (prob is scaled - see MINSTREL_FRAC above)
+ */
+ if (prob_ewma > MINSTREL_FRAC(90, 100))
+ return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
+ / nsecs));
+ else
+ return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
}
/*
@@ -364,14 +361,15 @@
cur_group = index / MCS_GROUP_RATES;
cur_idx = index % MCS_GROUP_RATES;
- cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx);
cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
+ cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
do {
tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
- tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx);
tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+ tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
+ tmp_prob);
if (cur_tp_avg < tmp_tp_avg ||
(cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
break;
@@ -396,8 +394,8 @@
struct minstrel_rate_stats *mrs;
int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
int max_tp_group, cur_tp_avg, cur_group, cur_idx;
- int max_group_prob_rate_group, max_group_prob_rate_idx;
- int max_group_prob_rate_tp_avg;
+ int max_gpr_group, max_gpr_idx;
+ int max_gpr_tp_avg, max_gpr_prob;
cur_group = index / MCS_GROUP_RATES;
cur_idx = index % MCS_GROUP_RATES;
@@ -406,8 +404,8 @@
tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
- tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx);
tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+ tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
/* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
* MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
@@ -417,18 +415,18 @@
return;
if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
- cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx);
+ cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
+ mrs->prob_ewma);
if (cur_tp_avg > tmp_tp_avg)
mi->max_prob_rate = index;
- max_group_prob_rate_group = mg->max_group_prob_rate /
- MCS_GROUP_RATES;
- max_group_prob_rate_idx = mg->max_group_prob_rate %
- MCS_GROUP_RATES;
- max_group_prob_rate_tp_avg = minstrel_ht_get_tp_avg(mi,
- max_group_prob_rate_group,
- max_group_prob_rate_idx);
- if (cur_tp_avg > max_group_prob_rate_tp_avg)
+ max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
+ max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
+ max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
+ max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
+ max_gpr_idx,
+ max_gpr_prob);
+ if (cur_tp_avg > max_gpr_tp_avg)
mg->max_group_prob_rate = index;
} else {
if (mrs->prob_ewma > tmp_prob)
@@ -450,16 +448,18 @@
u16 tmp_mcs_tp_rate[MAX_THR_RATES],
u16 tmp_cck_tp_rate[MAX_THR_RATES])
{
- unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp;
+ unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
int i;
tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
- tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx);
+ tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+ tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
- tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx);
+ tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
+ tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
if (tmp_cck_tp > tmp_mcs_tp) {
for(i = 0; i < MAX_THR_RATES; i++) {
@@ -478,7 +478,7 @@
minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
{
struct minstrel_mcs_group_data *mg;
- int tmp_max_streams, group, tmp_idx;
+ int tmp_max_streams, group, tmp_idx, tmp_prob;
int tmp_tp = 0;
tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
@@ -489,12 +489,14 @@
continue;
tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
+ tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
- if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx) &&
+ if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
(minstrel_mcs_groups[group].streams < tmp_max_streams)) {
mi->max_prob_rate = mg->max_group_prob_rate;
tmp_tp = minstrel_ht_get_tp_avg(mi, group,
- tmp_idx);
+ tmp_idx,
+ tmp_prob);
}
}
}
@@ -513,7 +515,7 @@
{
struct minstrel_mcs_group_data *mg;
struct minstrel_rate_stats *mrs;
- int group, i, j;
+ int group, i, j, cur_prob;
u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
@@ -555,8 +557,9 @@
mrs = &mg->rates[i];
mrs->retry_updated = false;
minstrel_calc_rate_stats(mrs);
+ cur_prob = mrs->prob_ewma;
- if (minstrel_ht_get_tp_avg(mi, group, i) == 0)
+ if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
continue;
/* Find max throughput rate set */
@@ -1315,16 +1318,17 @@
{
struct minstrel_ht_sta_priv *msp = priv_sta;
struct minstrel_ht_sta *mi = &msp->ht;
- int i, j, tp_avg;
+ int i, j, prob, tp_avg;
if (!msp->is_ht)
return mac80211_minstrel.get_expected_throughput(priv_sta);
i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
+ prob = mi->groups[i].rates[j].prob_ewma;
/* convert tp_avg from pkt per second in kbps */
- tp_avg = minstrel_ht_get_tp_avg(mi, i, j) * AVG_PKT_SIZE * 8 / 1024;
+ tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * AVG_PKT_SIZE * 8 / 1024;
return tp_avg;
}