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linux-next/net/mac80211/rc80211_minstrel.h
Thomas Huehn f744bf81f7 mac80211: add lowest rate into minstrel's random rate sampling table
While minstrel bootstraps and fills the success probabilities of each
rate the lowest rate has typically a very high success probability
(often 100% in our tests).
Its statistics are never updated but considered to setup the mrr chain.
In our tests we see that especially the 3rd mrr stage (which is that
rate providing highest success probability) is filled with the lowest rate
because its initial high sucess probability is never updated. By design
the 4th mrr stage is filled with the lowest rate so often 3rd and 4th
mrr stage are equal.

This patch follows minstrels general approach of assuming as little
as possible about rate dependencies. Consequently we include the
lowest rate into the random sampling table to get balanced up-to-date
statistics of all rates and therefore balanced decisions.

Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-06 16:36:09 +01:00

131 lines
2.8 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 75 /* ewma weighting factor [%] */
#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)
/*
* Perform EWMA (Exponentially Weighted Moving Average) calculation
*/
static inline int
minstrel_ewma(int old, int new, int weight)
{
return (new * (100 - weight) + old * weight) / 100;
}
struct minstrel_rate {
int bitrate;
int rix;
unsigned int perfect_tx_time;
unsigned int ack_time;
int sample_limit;
unsigned int retry_count;
unsigned int retry_count_cts;
unsigned int retry_count_rtscts;
unsigned int adjusted_retry_count;
u32 success;
u32 attempts;
u32 last_attempts;
u32 last_success;
u8 sample_skipped;
/* parts per thousand */
u32 cur_prob;
u32 probability;
/* per-rate throughput */
u32 cur_tp;
u64 succ_hist;
u64 att_hist;
};
struct minstrel_sta_info {
unsigned long stats_update;
unsigned int sp_ack_dur;
unsigned int rate_avg;
unsigned int lowest_rix;
unsigned int max_tp_rate;
unsigned int max_tp_rate2;
unsigned int max_prob_rate;
unsigned int packet_count;
unsigned int sample_count;
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;
#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 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);
/* debugfs */
int minstrel_stats_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