From 11d70f0600921702af63c10a9482029b072dbf0b Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 3 Mar 2018 18:51:49 +0100 Subject: [PATCH] mac80211: avoid sampling rates that are too slow, improves throughput Signed-off-by: Felix Fietkau --- ...l-do-not-sample-rates-3-times-slower.patch | 40 +++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 package/kernel/mac80211/patches/377-mac80211-minstrel-do-not-sample-rates-3-times-slower.patch diff --git a/package/kernel/mac80211/patches/377-mac80211-minstrel-do-not-sample-rates-3-times-slower.patch b/package/kernel/mac80211/patches/377-mac80211-minstrel-do-not-sample-rates-3-times-slower.patch new file mode 100644 index 0000000000..414cb137de --- /dev/null +++ b/package/kernel/mac80211/patches/377-mac80211-minstrel-do-not-sample-rates-3-times-slower.patch @@ -0,0 +1,40 @@ +From: Felix Fietkau +Date: Sat, 3 Mar 2018 18:48:58 +0100 +Subject: [PATCH] mac80211: minstrel: do not sample rates 3 times slower than + max_prob_rate + +These rates are highly unlikely to be used quickly, even if the link +deteriorates rapidly. This improves throughput in cases where CCK rates +are not reliable enough to be skipped entirely during sampling. +Sampling these rates regularly can cost a lot of airtime. + +Signed-off-by: Felix Fietkau +--- + +--- a/net/mac80211/rc80211_minstrel_ht.c ++++ b/net/mac80211/rc80211_minstrel_ht.c +@@ -1004,10 +1004,13 @@ minstrel_get_sample_rate(struct minstrel + return -1; + + /* +- * Do not sample if the probability is already higher than 95% +- * to avoid wasting airtime. ++ * Do not sample if the probability is already higher than 95%, ++ * or if the rate is 3 times slower than the current max probability ++ * rate, to avoid wasting airtime. + */ +- if (mrs->prob_ewma > MINSTREL_FRAC(95, 100)) ++ sample_dur = minstrel_get_duration(sample_idx); ++ if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || ++ minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur) + return -1; + + /* +@@ -1017,7 +1020,6 @@ minstrel_get_sample_rate(struct minstrel + + 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(tp_rate2) && + (cur_max_tp_streams - 1 < + minstrel_mcs_groups[sample_group].streams ||