minstrel: improve performance for non-MRR drivers

This patch enhances minstrel's performance for non-MRR setups,
by preventing it from sampling slower rates with >95% success
probability and by putting at least 1 non-sample frame between
several sample frames.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Felix Fietkau 2008-10-15 19:13:59 +02:00 committed by John W. Linville
parent 0a9542ee12
commit f4a8cd94fc
2 changed files with 27 additions and 4 deletions

View File

@ -126,7 +126,9 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
mr->adjusted_retry_count = mr->retry_count >> 1;
if (mr->adjusted_retry_count > 2)
mr->adjusted_retry_count = 2;
mr->sample_limit = 4;
} else {
mr->sample_limit = -1;
mr->adjusted_retry_count = mr->retry_count;
}
if (!mr->adjusted_retry_count)
@ -265,7 +267,8 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
(mi->sample_count + mi->sample_deferred / 2);
/* delta > 0: sampling required */
if (delta > 0) {
if ((delta > 0) && (mrr || !mi->prev_sample)) {
struct minstrel_rate *msr;
if (mi->packet_count >= 10000) {
mi->sample_deferred = 0;
mi->sample_count = 0;
@ -284,13 +287,20 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
}
sample_ndx = minstrel_get_next_sample(mi);
msr = &mi->r[sample_ndx];
sample = true;
sample_slower = mrr && (mi->r[sample_ndx].perfect_tx_time >
sample_slower = mrr && (msr->perfect_tx_time >
mi->r[ndx].perfect_tx_time);
if (!sample_slower) {
ndx = sample_ndx;
mi->sample_count++;
if (msr->sample_limit != 0) {
ndx = sample_ndx;
mi->sample_count++;
if (msr->sample_limit > 0)
msr->sample_limit--;
} else {
sample = false;
}
} else {
/* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark
* packets that have the sampling rate deferred to the
@ -302,10 +312,20 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
mi->sample_deferred++;
}
}
mi->prev_sample = sample;
/* If we're not using MRR and the sampling rate already
* has a probability of >95%, we shouldn't be attempting
* to use it, as this only wastes precious airtime */
if (!mrr && sample && (mi->r[ndx].probability > 17100))
ndx = mi->max_tp_rate;
ar[0].idx = mi->r[ndx].rix;
ar[0].count = minstrel_get_retry_count(&mi->r[ndx], info);
if (!mrr) {
if (!sample)
ar[0].count = mp->max_retry;
ar[1].idx = mi->lowest_rix;
ar[1].count = mp->max_retry;
return;
@ -401,6 +421,7 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
/* calculate maximum number of retransmissions before
* fallback (based on maximum segment size) */
mr->sample_limit = -1;
mr->retry_count = 1;
mr->retry_count_cts = 1;
mr->retry_count_rtscts = 1;

View File

@ -16,6 +16,7 @@ struct minstrel_rate {
unsigned int perfect_tx_time;
unsigned int ack_time;
int sample_limit;
unsigned int retry_count;
unsigned int retry_count_cts;
unsigned int retry_count_rtscts;
@ -57,6 +58,7 @@ struct minstrel_sta_info {
int n_rates;
struct minstrel_rate *r;
bool prev_sample;
/* sampling table */
u8 *sample_table;