forked from Minki/linux
5f919abc76
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>
171 lines
4.2 KiB
C
171 lines
4.2 KiB
C
/*
|
|
* Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#ifndef __RC_MINSTREL_H
|
|
#define __RC_MINSTREL_H
|
|
|
|
#define EWMA_LEVEL 96 /* ewma weighting factor [/EWMA_DIV] */
|
|
#define EWMA_DIV 128
|
|
#define SAMPLE_COLUMNS 10 /* number of columns in sample table */
|
|
|
|
/* scaled fraction values */
|
|
#define MINSTREL_SCALE 16
|
|
#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
|
|
#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
|
|
|
|
/* number of highest throughput rates to consider*/
|
|
#define MAX_THR_RATES 4
|
|
|
|
/*
|
|
* Perform EWMA (Exponentially Weighted Moving Average) calculation
|
|
*/
|
|
static inline int
|
|
minstrel_ewma(int old, int new, int weight)
|
|
{
|
|
int diff, incr;
|
|
|
|
diff = new - old;
|
|
incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
|
|
|
|
return old + incr;
|
|
}
|
|
|
|
/*
|
|
* Perform EWMSD (Exponentially Weighted Moving Standard Deviation) calculation
|
|
*/
|
|
static inline int
|
|
minstrel_ewmsd(int old_ewmsd, int cur_prob, int prob_ewma, int weight)
|
|
{
|
|
int diff, incr, tmp_var;
|
|
|
|
/* calculate exponential weighted moving variance */
|
|
diff = MINSTREL_TRUNC((cur_prob - prob_ewma) * 1000000);
|
|
incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
|
|
tmp_var = old_ewmsd * old_ewmsd;
|
|
tmp_var = weight * (tmp_var + diff * incr / 1000000) / EWMA_DIV;
|
|
|
|
/* return standard deviation */
|
|
return (u16) int_sqrt(tmp_var);
|
|
}
|
|
|
|
struct minstrel_rate_stats {
|
|
/* current / last sampling period attempts/success counters */
|
|
u16 attempts, last_attempts;
|
|
u16 success, last_success;
|
|
|
|
/* total attempts/success counters */
|
|
u64 att_hist, succ_hist;
|
|
|
|
/* statistis of packet delivery probability
|
|
* cur_prob - current prob within last update intervall
|
|
* prob_ewma - exponential weighted moving average of prob
|
|
* prob_ewmsd - exp. weighted moving standard deviation of prob */
|
|
unsigned int cur_prob;
|
|
unsigned int prob_ewma;
|
|
u16 prob_ewmsd;
|
|
|
|
/* maximum retry counts */
|
|
u8 retry_count;
|
|
u8 retry_count_rtscts;
|
|
|
|
u8 sample_skipped;
|
|
bool retry_updated;
|
|
};
|
|
|
|
struct minstrel_rate {
|
|
int bitrate;
|
|
|
|
s8 rix;
|
|
u8 retry_count_cts;
|
|
u8 adjusted_retry_count;
|
|
|
|
unsigned int perfect_tx_time;
|
|
unsigned int ack_time;
|
|
|
|
int sample_limit;
|
|
|
|
struct minstrel_rate_stats stats;
|
|
};
|
|
|
|
struct minstrel_sta_info {
|
|
struct ieee80211_sta *sta;
|
|
|
|
unsigned long last_stats_update;
|
|
unsigned int sp_ack_dur;
|
|
unsigned int rate_avg;
|
|
|
|
unsigned int lowest_rix;
|
|
|
|
u8 max_tp_rate[MAX_THR_RATES];
|
|
u8 max_prob_rate;
|
|
unsigned int total_packets;
|
|
unsigned int sample_packets;
|
|
int sample_deferred;
|
|
|
|
unsigned int sample_row;
|
|
unsigned int sample_column;
|
|
|
|
int n_rates;
|
|
struct minstrel_rate *r;
|
|
bool prev_sample;
|
|
|
|
/* sampling table */
|
|
u8 *sample_table;
|
|
|
|
#ifdef CONFIG_MAC80211_DEBUGFS
|
|
struct dentry *dbg_stats;
|
|
struct dentry *dbg_stats_csv;
|
|
#endif
|
|
};
|
|
|
|
struct minstrel_priv {
|
|
struct ieee80211_hw *hw;
|
|
bool has_mrr;
|
|
unsigned int cw_min;
|
|
unsigned int cw_max;
|
|
unsigned int max_retry;
|
|
unsigned int segment_size;
|
|
unsigned int update_interval;
|
|
unsigned int lookaround_rate;
|
|
unsigned int lookaround_rate_mrr;
|
|
|
|
u8 cck_rates[4];
|
|
|
|
#ifdef CONFIG_MAC80211_DEBUGFS
|
|
/*
|
|
* enable fixed rate processing per RC
|
|
* - write static index to debugfs:ieee80211/phyX/rc/fixed_rate_idx
|
|
* - write -1 to enable RC processing again
|
|
* - setting will be applied on next update
|
|
*/
|
|
u32 fixed_rate_idx;
|
|
struct dentry *dbg_fixed_rate;
|
|
#endif
|
|
};
|
|
|
|
struct minstrel_debugfs_info {
|
|
size_t len;
|
|
char buf[];
|
|
};
|
|
|
|
extern const struct rate_control_ops mac80211_minstrel;
|
|
void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
|
|
void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
|
|
|
|
/* Recalculate success probabilities and counters for a given rate using EWMA */
|
|
void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs);
|
|
int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
|
|
|
|
/* debugfs */
|
|
int minstrel_stats_open(struct inode *inode, struct file *file);
|
|
int minstrel_stats_csv_open(struct inode *inode, struct file *file);
|
|
ssize_t minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos);
|
|
int minstrel_stats_release(struct inode *inode, struct file *file);
|
|
|
|
#endif
|