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| author |   Felix Fietkau <nbd@nbd.name> | 2018-10-06 19:35:07 +0200 |
|---|---|---|
| committer |   Johannes Berg <johannes.berg@intel.com> | 2018-10-11 16:01:05 +0200 |
| commit | 506dbf90c1ba98d998b26e17a2e3e69bffef52f4 (patch) | |
| tree | c4476f0b470499290908109f3259d192e71ee1b5 /net/mac80211/rc80211_minstrel.h | |
| parent | mac80211: minstrel: do not sample rates 3 times slower than max_prob_rate (diff) | |
| download | linux-dev-506dbf90c1ba98d998b26e17a2e3e69bffef52f4.tar.xz linux-dev-506dbf90c1ba98d998b26e17a2e3e69bffef52f4.zip | |
mac80211: rc80211_minstrel: remove variance / stddev calculation
When there are few packets (e.g. for sampling attempts), the exponentially
weighted variance is usually vastly overestimated, making the resulting data
essentially useless. As far as I know, there has not been any practical use
for this, so let's not waste any cycles on it.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/rc80211_minstrel.h')
| -rw-r--r-- | net/mac80211/rc80211_minstrel.h | 26 |
1 files changed, 1 insertions, 25 deletions
diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h index 54b2b2c3e10a..23ec953e3a24 100644 --- a/net/mac80211/rc80211_minstrel.h +++ b/net/mac80211/rc80211_minstrel.h @@ -35,19 +35,6 @@ minstrel_ewma(int old, int new, int weight) return old + incr; } -/* - * Perform EWMV (Exponentially Weighted Moving Variance) calculation - */ -static inline int -minstrel_ewmv(int old_ewmv, int cur_prob, int prob_ewma, int weight) -{ - int diff, incr; - - diff = cur_prob - prob_ewma; - incr = (EWMA_DIV - weight) * diff / EWMA_DIV; - return weight * (old_ewmv + MINSTREL_TRUNC(diff * incr)) / EWMA_DIV; -} - struct minstrel_rate_stats { /* current / last sampling period attempts/success counters */ u16 attempts, last_attempts; @@ -56,11 +43,8 @@ struct minstrel_rate_stats { /* total attempts/success counters */ u32 att_hist, succ_hist; - /* statistis of packet delivery probability - * prob_ewma - exponential weighted moving average of prob - * prob_ewmsd - exp. weighted moving standard deviation of prob */ + /* prob_ewma - exponential weighted moving average of prob */ u16 prob_ewma; - u16 prob_ewmv; /* maximum retry counts */ u8 retry_count; @@ -140,14 +124,6 @@ struct minstrel_debugfs_info { char buf[]; }; -/* Get EWMSD (Exponentially Weighted Moving Standard Deviation) * 10 */ -static inline int -minstrel_get_ewmsd10(struct minstrel_rate_stats *mrs) -{ - unsigned int ewmv = mrs->prob_ewmv; - return int_sqrt(MINSTREL_TRUNC(ewmv * 1000 * 1000)); -} - extern const struct rate_control_ops mac80211_minstrel; void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir); |