78 lines
2.8 KiB
Diff
78 lines
2.8 KiB
Diff
|
From: Felix Fietkau <nbd@openwrt.org>
|
||
|
|
Date: Thu, 3 Mar 2016 23:20:06 +0100
|
||
|
|
Subject: [PATCH] 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: Felix Fietkau <nbd@openwrt.org>
|
||
|
|
---
|
||
|
|
|
||
|
|
--- a/net/mac80211/rc80211_minstrel_ht.c
|
||
|
|
+++ b/net/mac80211/rc80211_minstrel_ht.c
|
||
|
|
@@ -958,6 +958,7 @@ minstrel_get_sample_rate(struct minstrel
|
||
|
|
struct minstrel_rate_stats *mrs;
|
||
|
|
struct minstrel_mcs_group_data *mg;
|
||
|
|
unsigned int sample_dur, sample_group, cur_max_tp_streams;
|
||
|
|
+ int tp_rate1, tp_rate2;
|
||
|
|
int sample_idx = 0;
|
||
|
|
|
||
|
|
if (mi->sample_wait > 0) {
|
||
|
|
@@ -979,14 +980,22 @@ minstrel_get_sample_rate(struct minstrel
|
||
|
|
mrs = &mg->rates[sample_idx];
|
||
|
|
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)
|
||
|
|
- * to the frame. Hence, don't use sampling for the currently
|
||
|
|
- * used rates.
|
||
|
|
+ * to the frame. Hence, don't use sampling for the highest currently
|
||
|
|
+ * used highest throughput or probability rate.
|
||
|
|
*/
|
||
|
|
- if (sample_idx == mi->max_tp_rate[0] ||
|
||
|
|
- sample_idx == mi->max_tp_rate[1] ||
|
||
|
|
- sample_idx == mi->max_prob_rate)
|
||
|
|
+ if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
/*
|
||
|
|
@@ -1001,10 +1010,10 @@ minstrel_get_sample_rate(struct minstrel
|
||
|
|
* 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;
|
||
|
|
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 <
|
||
|
|
minstrel_mcs_groups[sample_group].streams ||
|
||
|
|
sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
|