diff options
| author |   Thomas Huehn <thomas@net.t-labs.tu-berlin.de> | 2015-03-24 21:09:43 +0100 |
|---|---|---|
| committer |   Johannes Berg <johannes.berg@intel.com> | 2015-04-01 20:44:33 +0200 |
| commit | 5f919abc76fc3de1e5965ea03c925f7563c7fc15 (patch) | |
| tree | 8ed67f827d3b66cbfb140c66d8cd2d0f115633a6 /net/mac80211/rc80211_minstrel.c | |
| parent | mac80211: reduce calculation costs of EWMA (diff) | |
| download | linux-dev-5f919abc76fc3de1e5965ea03c925f7563c7fc15.tar.xz linux-dev-5f919abc76fc3de1e5965ea03c925f7563c7fc15.zip | |
mac80211: add standard deviation to Minstrel stats
This patch adds the statistical descriptor "standard deviation"
to better describe the current properties of Minstrel and
Minstrel-HTs success probability distribution. The standard
deviation (SD) is calculated as exponential weighted moving
standard deviation (EWMSD) and its current value is added as
new column in all rc_stats (in debugfs).
Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/rc80211_minstrel.c')
| -rw-r--r-- | net/mac80211/rc80211_minstrel.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c index c4a3477812ee..247552a7f6c2 100644 --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -153,7 +153,7 @@ minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi) } /* -* Recalculate success probabilities and counters for a given rate using EWMA +* Recalculate statistics and counters of a given rate */ void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs) @@ -161,11 +161,20 @@ minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs) if (unlikely(mrs->attempts > 0)) { mrs->sample_skipped = 0; mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); - if (unlikely(!mrs->att_hist)) + if (unlikely(!mrs->att_hist)) { mrs->prob_ewma = mrs->cur_prob; - else + } else { + /* update exponential weighted moving variance */ + mrs->prob_ewmsd = minstrel_ewmsd(mrs->prob_ewmsd, + mrs->cur_prob, + mrs->prob_ewma, + EWMA_LEVEL); + + /*update exponential weighted moving avarage */ mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma, - mrs->cur_prob, EWMA_LEVEL); + mrs->cur_prob, + EWMA_LEVEL); + } mrs->att_hist += mrs->attempts; mrs->succ_hist += mrs->success; } else { @@ -193,7 +202,7 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) struct minstrel_rate_stats *mrs = &mi->r[i].stats; struct minstrel_rate_stats *tmp_mrs = &mi->r[tmp_prob_rate].stats; - /* Update success probabilities per rate */ + /* Update statistics of success probability per rate */ minstrel_calc_rate_stats(mrs); /* Sample less often below the 10% chance of success. |