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| author | Felix Fietkau <nbd@openwrt.org> | 2016-03-03 23:25:42 +0100 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2016-04-05 11:40:06 +0200 |
| commit | 06171e9c0bd54bd7dde67dfb2fa4cced23cff880 (patch) | |
| tree | 5231a7933947f2163e395e105f425dde6f184082 /net/mac80211 | |
| parent | 07310a63147164eaf44a68932fbe9dbbde0fa82b (diff) | |
| download | linux-06171e9c0bd54bd7dde67dfb2fa4cced23cff880.tar.gz linux-06171e9c0bd54bd7dde67dfb2fa4cced23cff880.tar.bz2 linux-06171e9c0bd54bd7dde67dfb2fa4cced23cff880.zip | |
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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211')
| -rw-r--r-- | net/mac80211/rc80211_minstrel_ht.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 370d677b547b..46ce08ed70b5 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -924,6 +924,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 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) { @@ -945,14 +946,22 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 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; /* @@ -967,10 +976,10 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) * 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))) { |