Commit 06171e9c authored by Felix Fietkau's avatar Felix Fietkau Committed by Johannes Berg

mac80211: minstrel_ht: improve sample rate skip logic

There were a few issues that were slowing down the process of finding
the optimal rate, especially on devices with multi-rate retry
limitations:

When max_tp_rate[0] was slower than max_tp_rate[1], the code did not
sample max_tp_rate[1], which would often allow it to switch places with
max_tp_rate[0] (e.g. if only the first sampling attempts were bad, but the
rate is otherwise good).

Also, sample attempts of rates between max_tp_rate[0] and [1] were being
ignored in this case, because the code only checked if the rate was
slower than [1].

Fix this by checking against the fastest / second fastest max_tp_rate
instead of assuming a specific order between the two.

In my tests this patch significantly reduces the time until minstrel_ht
finds the optimal rate right after assoc
Signed-off-by: default avatarFelix Fietkau <nbd@openwrt.org>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 07310a63
...@@ -924,6 +924,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) ...@@ -924,6 +924,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
struct minstrel_rate_stats *mrs; struct minstrel_rate_stats *mrs;
struct minstrel_mcs_group_data *mg; struct minstrel_mcs_group_data *mg;
unsigned int sample_dur, sample_group, cur_max_tp_streams; unsigned int sample_dur, sample_group, cur_max_tp_streams;
int tp_rate1, tp_rate2;
int sample_idx = 0; int sample_idx = 0;
if (mi->sample_wait > 0) { if (mi->sample_wait > 0) {
...@@ -945,14 +946,22 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) ...@@ -945,14 +946,22 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
mrs = &mg->rates[sample_idx]; mrs = &mg->rates[sample_idx];
sample_idx += sample_group * MCS_GROUP_RATES; sample_idx += sample_group * MCS_GROUP_RATES;
/* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
if (minstrel_get_duration(mi->max_tp_rate[0]) >
minstrel_get_duration(mi->max_tp_rate[1])) {
tp_rate1 = mi->max_tp_rate[1];
tp_rate2 = mi->max_tp_rate[0];
} else {
tp_rate1 = mi->max_tp_rate[0];
tp_rate2 = mi->max_tp_rate[1];
}
/* /*
* Sampling might add some overhead (RTS, no aggregation) * Sampling might add some overhead (RTS, no aggregation)
* to the frame. Hence, don't use sampling for the currently * to the frame. Hence, don't use sampling for the highest currently
* used rates. * used highest throughput or probability rate.
*/ */
if (sample_idx == mi->max_tp_rate[0] || if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
sample_idx == mi->max_tp_rate[1] ||
sample_idx == mi->max_prob_rate)
return -1; return -1;
/* /*
...@@ -967,10 +976,10 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) ...@@ -967,10 +976,10 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
* if the link is working perfectly. * if the link is working perfectly.
*/ */
cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
MCS_GROUP_RATES].streams; MCS_GROUP_RATES].streams;
sample_dur = minstrel_get_duration(sample_idx); sample_dur = minstrel_get_duration(sample_idx);
if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) && if (sample_dur >= minstrel_get_duration(tp_rate2) &&
(cur_max_tp_streams - 1 < (cur_max_tp_streams - 1 <
minstrel_mcs_groups[sample_group].streams || minstrel_mcs_groups[sample_group].streams ||
sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment