77 lines
2.8 KiB
Diff
77 lines
2.8 KiB
Diff
From: Felix Fietkau <nbd@openwrt.org>
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Date: Thu, 3 Mar 2016 23:20:06 +0100
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Subject: [PATCH] mac80211: minstrel_ht: improve sample rate skip logic
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There were a few issues that were slowing down the process of finding
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the optimal rate, especially on devices with multi-rate retry
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limitations:
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When max_tp_rate[0] was slower than max_tp_rate[1], the code did not
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sample max_tp_rate[1], which would often allow it to switch places with
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max_tp_rate[0] (e.g. if only the first sampling attempts were bad, but the
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rate is otherwise good).
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Also, sample attempts of rates between max_tp_rate[0] and [1] were being
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ignored in this case, because the code only checked if the rate was
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slower than [1].
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Fix this by checking against the fastest / second fastest max_tp_rate
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instead of assuming a specific order between the two.
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In my tests this patch significantly reduces the time until minstrel_ht
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finds the optimal rate right after assoc
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Signed-off-by: Felix Fietkau <nbd@openwrt.org>
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---
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--- a/net/mac80211/rc80211_minstrel_ht.c
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+++ b/net/mac80211/rc80211_minstrel_ht.c
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@@ -958,6 +958,7 @@ minstrel_get_sample_rate(struct minstrel
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struct minstrel_rate_stats *mrs;
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struct minstrel_mcs_group_data *mg;
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unsigned int sample_dur, sample_group, cur_max_tp_streams;
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+ int tp_rate1, tp_rate2;
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int sample_idx = 0;
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if (mi->sample_wait > 0) {
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@@ -979,14 +980,22 @@ minstrel_get_sample_rate(struct minstrel
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mrs = &mg->rates[sample_idx];
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sample_idx += sample_group * MCS_GROUP_RATES;
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+ /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
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+ if (minstrel_get_duration(mi->max_tp_rate[0]) >
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+ minstrel_get_duration(mi->max_tp_rate[1])) {
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+ tp_rate1 = mi->max_tp_rate[1];
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+ tp_rate2 = mi->max_tp_rate[0];
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+ } else {
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+ tp_rate1 = mi->max_tp_rate[0];
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+ tp_rate2 = mi->max_tp_rate[1];
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+ }
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+
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/*
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* Sampling might add some overhead (RTS, no aggregation)
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- * to the frame. Hence, don't use sampling for the currently
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- * used rates.
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+ * to the frame. Hence, don't use sampling for the highest currently
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+ * used highest throughput or probability rate.
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*/
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- if (sample_idx == mi->max_tp_rate[0] ||
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- sample_idx == mi->max_tp_rate[1] ||
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- sample_idx == mi->max_prob_rate)
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+ if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
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return -1;
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/*
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@@ -1001,10 +1010,10 @@ minstrel_get_sample_rate(struct minstrel
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* if the link is working perfectly.
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*/
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- cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
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+ cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
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MCS_GROUP_RATES].streams;
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sample_dur = minstrel_get_duration(sample_idx);
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- if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
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+ if (sample_dur >= minstrel_get_duration(tp_rate2) &&
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(cur_max_tp_streams - 1 <
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minstrel_mcs_groups[sample_group].streams ||
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sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
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