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NetBSD/sys/dev/ic/athrate-sample.c

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/* $NetBSD: athrate-sample.c,v 1.13 2007/10/19 11:59:47 ad Exp $ */
/*-
* Copyright (c) 2005 John Bicket
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
* redistribution must be conditioned upon including a substantially
* similar Disclaimer requirement for further binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGES.
*/
#include <sys/cdefs.h>
#ifdef __FreeBSD__
__FBSDID("$FreeBSD: src/sys/dev/ath/ath_rate/sample/sample.c,v 1.9 2005/07/22 16:50:17 sam Exp $");
#endif
#ifdef __NetBSD__
__KERNEL_RCSID(0, "$NetBSD: athrate-sample.c,v 1.13 2007/10/19 11:59:47 ad Exp $");
#endif
/*
* John Bicket's SampleRate control algorithm.
*/
#include "opt_inet.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/errno.h>
#include <sys/device.h>
#include <sys/bus.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_media.h>
#include <net/if_arp.h>
#include <net/if_ether.h> /* XXX for ether_sprintf */
#include <net80211/ieee80211_var.h>
#include <net/bpf.h>
#ifdef INET
#include <netinet/in.h>
#endif
#include <dev/ic/athvar.h>
#include <dev/ic/athrate-sample.h>
#include <contrib/dev/ath/ah_desc.h>
#define SAMPLE_DEBUG
#ifdef SAMPLE_DEBUG
enum {
ATH_DEBUG_RATE = 0x00000010 /* rate control */
};
#define DPRINTF(sc, _fmt, ...) do { \
if (sc->sc_debug & ATH_DEBUG_RATE) \
printf(_fmt, __VA_ARGS__); \
} while (0)
#else
#define DPRINTF(sc, _fmt, ...)
#endif
/*
* This file is an implementation of the SampleRate algorithm
* in "Bit-rate Selection in Wireless Networks"
* (http://www.pdos.lcs.mit.edu/papers/jbicket-ms.ps)
*
* SampleRate chooses the bit-rate it predicts will provide the most
* throughput based on estimates of the expected per-packet
* transmission time for each bit-rate. SampleRate periodically sends
* packets at bit-rates other than the current one to estimate when
* another bit-rate will provide better performance. SampleRate
* switches to another bit-rate when its estimated per-packet
* transmission time becomes smaller than the current bit-rate's.
* SampleRate reduces the number of bit-rates it must sample by
* eliminating those that could not perform better than the one
* currently being used. SampleRate also stops probing at a bit-rate
* if it experiences several successive losses.
*
* The difference between the algorithm in the thesis and the one in this
* file is that the one in this file uses a ewma instead of a window.
*
* Also, this implementation tracks the average transmission time for
* a few different packet sizes independently for each link.
*/
#define STALE_FAILURE_TIMEOUT_MS 10000
#define MIN_SWITCH_MS 1000
static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
static inline int
size_to_bin(int size)
{
int x = 0;
for (x = 0; x < NUM_PACKET_SIZE_BINS; x++) {
if (size <= packet_size_bins[x]) {
return x;
}
}
return NUM_PACKET_SIZE_BINS-1;
}
static inline int bin_to_size(int index) {
return packet_size_bins[index];
}
static inline int
rate_to_ndx(struct sample_node *sn, int rate) {
int x = 0;
for (x = 0; x < sn->num_rates; x++) {
if (sn->rates[x].rate == rate) {
return x;
}
}
return -1;
}
void
ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
{
DPRINTF(sc, "%s:\n", __func__);
/* NB: assumed to be zero'd by caller */
}
void
ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
{
DPRINTF(sc, "%s:\n", __func__);
}
/*
* returns the ndx with the lowest average_tx_time,
* or -1 if all the average_tx_times are 0.
*/
static inline int best_rate_ndx(struct sample_node *sn, int size_bin,
int require_acked_before)
{
int x = 0;
int best_ndx = 0;
int best_rate_tt = 0;
for (x = 0; x < sn->num_rates; x++) {
int tt = sn->stats[size_bin][x].average_tx_time;
if (tt <= 0 || (require_acked_before &&
!sn->stats[size_bin][x].packets_acked)) {
continue;
}
/* 9 megabits never works better than 12 */
if (sn->rates[x].rate == 18)
continue;
/* don't use a bit-rate that has been failing */
if (sn->stats[size_bin][x].successive_failures > 3)
continue;
if (!best_rate_tt || best_rate_tt > tt) {
best_rate_tt = tt;
best_ndx = x;
}
}
return (best_rate_tt) ? best_ndx : -1;
}
/*
* pick a good "random" bit-rate to sample other than the current one
*/
static inline int
pick_sample_ndx(struct sample_node *sn, int size_bin)
{
int x = 0;
int current_ndx = 0;
unsigned current_tt = 0;
current_ndx = sn->current_rate[size_bin];
if (current_ndx < 0) {
/* no successes yet, send at the lowest bit-rate */
return 0;
}
current_tt = sn->stats[size_bin][current_ndx].average_tx_time;
for (x = 0; x < sn->num_rates; x++) {
int ndx = (sn->last_sample_ndx[size_bin]+1+x) % sn->num_rates;
/* don't sample the current bit-rate */
if (ndx == current_ndx)
continue;
/* this bit-rate is always worse than the current one */
if (sn->stats[size_bin][ndx].perfect_tx_time > current_tt)
continue;
/* rarely sample bit-rates that fail a lot */
if (ticks - sn->stats[size_bin][ndx].last_tx < ((hz * STALE_FAILURE_TIMEOUT_MS)/1000) &&
sn->stats[size_bin][ndx].successive_failures > 3)
continue;
/* don't sample more than 2 indexes higher
* for rates higher than 11 megabits
*/
if (sn->rates[ndx].rate > 22 && ndx > current_ndx + 2)
continue;
/* 9 megabits never works better than 12 */
if (sn->rates[ndx].rate == 18)
continue;
/* if we're using 11 megabits, only sample up to 12 megabits
*/
if (sn->rates[current_ndx].rate == 22 && ndx > current_ndx + 1)
continue;
sn->last_sample_ndx[size_bin] = ndx;
return ndx;
}
return current_ndx;
}
void
ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
int shortPreamble, size_t frameLen,
u_int8_t *rix, int *try0, u_int8_t *txrate)
{
struct sample_node *sn = ATH_NODE_SAMPLE(an);
struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
struct ieee80211com *ic = &sc->sc_ic;
int ndx, size_bin, mrr, best_ndx, change_rates;
unsigned average_tx_time;
mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
size_bin = size_to_bin(frameLen);
best_ndx = best_rate_ndx(sn, size_bin, !mrr);
if (best_ndx >= 0) {
average_tx_time = sn->stats[size_bin][best_ndx].average_tx_time;
} else {
average_tx_time = 0;
}
if (sn->static_rate_ndx != -1) {
ndx = sn->static_rate_ndx;
*try0 = ATH_TXMAXTRY;
} else {
*try0 = mrr ? 2 : ATH_TXMAXTRY;
if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->ath_sample_rate/100)) {
/*
* we want to limit the time measuring the performance
* of other bit-rates to ath_sample_rate% of the
* total transmission time.
*/
ndx = pick_sample_ndx(sn, size_bin);
if (ndx != sn->current_rate[size_bin]) {
sn->current_sample_ndx[size_bin] = ndx;
} else {
sn->current_sample_ndx[size_bin] = -1;
}
sn->packets_since_sample[size_bin] = 0;
} else {
change_rates = 0;
if (!sn->packets_sent[size_bin] || best_ndx == -1) {
/* no packet has been sent successfully yet */
for (ndx = sn->num_rates-1; ndx > 0; ndx--) {
/*
* pick the highest rate <= 36 Mbps
* that hasn't failed.
*/
if (sn->rates[ndx].rate <= 72 &&
sn->stats[size_bin][ndx].successive_failures == 0) {
break;
}
}
change_rates = 1;
best_ndx = ndx;
} else if (sn->packets_sent[size_bin] < 20) {
/* let the bit-rate switch quickly during the first few packets */
change_rates = 1;
} else if (ticks - ((hz*MIN_SWITCH_MS)/1000) > sn->ticks_since_switch[size_bin]) {
/* 2 seconds have gone by */
change_rates = 1;
} else if (average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time) {
/* the current bit-rate is twice as slow as the best one */
change_rates = 1;
}
sn->packets_since_sample[size_bin]++;
if (change_rates) {
if (best_ndx != sn->current_rate[size_bin]) {
DPRINTF(sc, "%s: %s size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d\n",
__func__,
ether_sprintf(an->an_node.ni_macaddr),
packet_size_bins[size_bin],
sn->rates[sn->current_rate[size_bin]].rate,
sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time,
sn->stats[size_bin][sn->current_rate[size_bin]].perfect_tx_time,
sn->rates[best_ndx].rate,
sn->stats[size_bin][best_ndx].average_tx_time,
sn->stats[size_bin][best_ndx].perfect_tx_time,
sn->packets_since_switch[size_bin],
mrr);
}
sn->packets_since_switch[size_bin] = 0;
sn->current_rate[size_bin] = best_ndx;
sn->ticks_since_switch[size_bin] = ticks;
}
ndx = sn->current_rate[size_bin];
sn->packets_since_switch[size_bin]++;
if (size_bin == 0) {
/*
* set the visible txrate for this node
* to the rate of small packets
*/
an->an_node.ni_txrate = ndx;
}
}
}
KASSERT(ndx >= 0 && ndx < sn->num_rates, ("ndx is %d", ndx));
*rix = sn->rates[ndx].rix;
if (shortPreamble) {
*txrate = sn->rates[ndx].shortPreambleRateCode;
} else {
*txrate = sn->rates[ndx].rateCode;
}
sn->packets_sent[size_bin]++;
}
void
ath_rate_setupxtxdesc(struct ath_softc *sc, struct ath_node *an,
struct ath_desc *ds, int shortPreamble, u_int8_t rix)
{
struct sample_node *sn = ATH_NODE_SAMPLE(an);
int rateCode = -1;
int frame_size = 0;
int size_bin = 0;
int ndx = 0;
size_bin = size_to_bin(frame_size); // TODO: it's correct that frame_size alway 0 ?
ndx = sn->current_rate[size_bin]; /* retry at the current bit-rate */
if (!sn->stats[size_bin][ndx].packets_acked) {
ndx = 0; /* use the lowest bit-rate */
}
if (shortPreamble) {
rateCode = sn->rates[ndx].shortPreambleRateCode;
} else {
rateCode = sn->rates[ndx].rateCode;
}
ath_hal_setupxtxdesc(sc->sc_ah, ds
, rateCode, 3 /* series 1 */
, sn->rates[0].rateCode, 3 /* series 2 */
, 0, 0 /* series 3 */
);
}
static void
update_stats(struct ath_softc *sc, struct ath_node *an,
int frame_size,
int ndx0, int tries0,
int ndx1, int tries1,
int ndx2, int tries2,
int ndx3, int tries3,
int short_tries, int tries, int status)
{
struct sample_node *sn = ATH_NODE_SAMPLE(an);
struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
int tt = 0;
int tries_so_far = 0;
int size_bin;
int size;
int rate;
if (ndx0 == -1)
return;
size_bin = size_to_bin(frame_size);
size = bin_to_size(size_bin);
rate = sn->rates[ndx0].rate;
tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix,
short_tries - 1, MIN(tries0, tries) - 1);
tries_so_far += tries0;
if (tries1 && tries0 < tries) {
tt += calc_usecs_unicast_packet(sc, size,
ndx1 == -1 ? 0 : sn->rates[ndx1].rix, short_tries - 1,
MIN(tries1 + tries_so_far, tries) - tries_so_far - 1);
}
tries_so_far += tries1;
if (tries2 && tries0 + tries1 < tries) {
tt += calc_usecs_unicast_packet(sc, size,
ndx2 == -1 ? 0 : sn->rates[ndx2].rix, short_tries - 1,
MIN(tries2 + tries_so_far, tries) - tries_so_far - 1);
}
tries_so_far += tries2;
if (tries3 && tries0 + tries1 + tries2 < tries) {
tt += calc_usecs_unicast_packet(sc, size,
ndx3 == -1 ? 0 : sn->rates[ndx3].rix, short_tries - 1,
MIN(tries3 + tries_so_far, tries) - tries_so_far - 1);
}
if (sn->stats[size_bin][ndx0].total_packets < (100 / (100 - ssc->ath_smoothing_rate))) {
/* just average the first few packets */
int avg_tx = sn->stats[size_bin][ndx0].average_tx_time;
int packets = sn->stats[size_bin][ndx0].total_packets;
sn->stats[size_bin][ndx0].average_tx_time = (tt+(avg_tx*packets))/(packets+1);
} else {
/* use a ewma */
sn->stats[size_bin][ndx0].average_tx_time =
((sn->stats[size_bin][ndx0].average_tx_time * ssc->ath_smoothing_rate) +
(tt * (100 - ssc->ath_smoothing_rate))) / 100;
}
if (status) {
int y;
sn->stats[size_bin][ndx0].successive_failures++;
for (y = size_bin+1; y < NUM_PACKET_SIZE_BINS; y++) {
/* also say larger packets failed since we
* assume if a small packet fails at a lower
* bit-rate then a larger one will also.
*/
sn->stats[y][ndx0].successive_failures++;
sn->stats[y][ndx0].last_tx = ticks;
sn->stats[y][ndx0].tries += tries;
sn->stats[y][ndx0].total_packets++;
}
} else {
sn->stats[size_bin][ndx0].packets_acked++;
sn->stats[size_bin][ndx0].successive_failures = 0;
}
sn->stats[size_bin][ndx0].tries += tries;
sn->stats[size_bin][ndx0].last_tx = ticks;
sn->stats[size_bin][ndx0].total_packets++;
if (ndx0 == sn->current_sample_ndx[size_bin]) {
DPRINTF(sc, "%s: %s size %d sample rate %d tries (%d/%d) tt %d avg_tt (%d/%d) status %d\n",
__func__, ether_sprintf(an->an_node.ni_macaddr),
size, rate, short_tries, tries, tt,
sn->stats[size_bin][ndx0].average_tx_time,
sn->stats[size_bin][ndx0].perfect_tx_time,
status);
sn->sample_tt[size_bin] = tt;
sn->current_sample_ndx[size_bin] = -1;
}
}
void
ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
const struct ath_desc *ds, const struct ath_desc *ds0)
{
struct ieee80211com *ic = &sc->sc_ic;
struct sample_node *sn = ATH_NODE_SAMPLE(an);
const struct ar5212_desc *ads = (const struct ar5212_desc *)&ds->ds_ctl0;
int final_rate, short_tries, long_tries, frame_size;
int ndx = -1;
int mrr;
final_rate = sc->sc_hwmap[ds->ds_txstat.ts_rate &~ HAL_TXSTAT_ALTRATE].ieeerate;
short_tries = ds->ds_txstat.ts_shortretry + 1;
long_tries = ds->ds_txstat.ts_longretry + 1;
frame_size = ds0->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */
if (frame_size == 0) /* NB: should not happen */
frame_size = 1500;
if (sn->num_rates <= 0) {
DPRINTF(sc, "%s: %s size %d status %d rate/try %d/%d "
"no rates yet\n",
__func__, ether_sprintf(an->an_node.ni_macaddr),
bin_to_size(size_to_bin(frame_size)),
ds->ds_txstat.ts_status,
short_tries, long_tries);
return;
}
mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT);
if (sc->sc_mrretry && ds->ds_txstat.ts_status) {
/* this packet failed */
DPRINTF(sc, "%s: %s size %d rate/try %d/%d %d/%d %d/%d %d/%d status %s retries (%d/%d)\n",
__func__,
ether_sprintf(an->an_node.ni_macaddr),
bin_to_size(size_to_bin(frame_size)),
sc->sc_hwmap[ads->xmit_rate0].ieeerate,
ads->xmit_tries0,
sc->sc_hwmap[ads->xmit_rate1].ieeerate,
ads->xmit_tries1,
sc->sc_hwmap[ads->xmit_rate2].ieeerate,
ads->xmit_tries2,
sc->sc_hwmap[ads->xmit_rate3].ieeerate,
ads->xmit_tries3,
ds->ds_txstat.ts_status ? "FAIL" : "OK",
short_tries,
long_tries);
}
if (!mrr || !(ds->ds_txstat.ts_rate & HAL_TXSTAT_ALTRATE)) {
/* only one rate was used */
ndx = rate_to_ndx(sn, final_rate);
DPRINTF(sc, "%s: %s size %d status %d rate/try %d/%d/%d\n",
__func__, ether_sprintf(an->an_node.ni_macaddr),
bin_to_size(size_to_bin(frame_size)),
ds->ds_txstat.ts_status,
ndx, short_tries, long_tries);
if (ndx >= 0 && ndx < sn->num_rates) {
update_stats(sc, an, frame_size,
ndx, long_tries,
0, 0,
0, 0,
0, 0,
short_tries, long_tries, ds->ds_txstat.ts_status);
}
} else {
int rate0, tries0, ndx0;
int rate1, tries1, ndx1;
int rate2, tries2, ndx2;
int rate3, tries3, ndx3;
int finalTSIdx = ads->final_ts_index;
/*
* Process intermediate rates that failed.
*/
rate0 = sc->sc_hwmap[ads->xmit_rate0].ieeerate;
tries0 = ads->xmit_tries0;
ndx0 = rate_to_ndx(sn, rate0);
rate1 = sc->sc_hwmap[ads->xmit_rate1].ieeerate;
tries1 = ads->xmit_tries1;
ndx1 = rate_to_ndx(sn, rate1);
rate2 = sc->sc_hwmap[ads->xmit_rate2].ieeerate;
tries2 = ads->xmit_tries2;
ndx2 = rate_to_ndx(sn, rate2);
rate3 = sc->sc_hwmap[ads->xmit_rate3].ieeerate;
tries3 = ads->xmit_tries3;
ndx3 = rate_to_ndx(sn, rate3);
#if 1
DPRINTF(sc, "%s: %s size %d finaltsidx %d tries %d status %d rate/try %d/%d %d/%d %d/%d %d/%d\n",
__func__, ether_sprintf(an->an_node.ni_macaddr),
bin_to_size(size_to_bin(frame_size)),
finalTSIdx,
long_tries,
ds->ds_txstat.ts_status,
rate0, tries0,
rate1, tries1,
rate2, tries2,
rate3, tries3);
#endif
if (tries0) {
update_stats(sc, an, frame_size,
ndx0, tries0,
ndx1, tries1,
ndx2, tries2,
ndx3, tries3,
short_tries, ds->ds_txstat.ts_longretry + 1,
long_tries > tries0);
}
if (tries1 && finalTSIdx > 0) {
update_stats(sc, an, frame_size,
ndx1, tries1,
ndx2, tries2,
ndx3, tries3,
0, 0,
short_tries, ds->ds_txstat.ts_longretry + 1 - tries0,
ds->ds_txstat.ts_status);
}
if (tries2 && finalTSIdx > 1) {
update_stats(sc, an, frame_size,
ndx2, tries2,
ndx3, tries3,
0, 0,
0, 0,
short_tries, ds->ds_txstat.ts_longretry + 1 - tries0 - tries1,
ds->ds_txstat.ts_status);
}
if (tries3 && finalTSIdx > 2) {
update_stats(sc, an, frame_size,
ndx3, tries3,
0, 0,
0, 0,
0, 0,
short_tries, ds->ds_txstat.ts_longretry + 1 - tries0 - tries1 - tries2,
ds->ds_txstat.ts_status);
}
}
}
void
ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
{
DPRINTF(sc, "%s: %s isnew %d\n", __func__,
ether_sprintf(an->an_node.ni_macaddr), isnew);
if (isnew)
ath_rate_ctl_reset(sc, &an->an_node);
}
/*
* Initialize the tables for a node.
*/
static void
ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
{
#define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
struct ieee80211com *ic = &sc->sc_ic;
struct ath_node *an = ATH_NODE(ni);
struct sample_node *sn = ATH_NODE_SAMPLE(an);
const HAL_RATE_TABLE *rt = sc->sc_currates;
int x, y, srate;
KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
sn->static_rate_ndx = -1;
if (ic->ic_fixed_rate != IEEE80211_FIXED_RATE_NONE) {
/*
* A fixed rate is to be used; ic_fixed_rate is an
* index into the supported rate set. Convert this
* to the index into the negotiated rate set for
* the node. We know the rate is there because the
* rate set is checked when the station associates.
*/
const struct ieee80211_rateset *rs =
&ic->ic_sup_rates[ic->ic_curmode];
int r = rs->rs_rates[ic->ic_fixed_rate] & IEEE80211_RATE_VAL;
/* NB: the rate set is assumed sorted */
srate = ni->ni_rates.rs_nrates - 1;
for (; srate >= 0 && RATE(srate) != r; srate--)
;
KASSERT(srate >= 0,
("fixed rate %d not in rate set", ic->ic_fixed_rate));
sn->static_rate_ndx = srate;
}
DPRINTF(sc, "%s: %s size 1600 rate/tt", __func__, ether_sprintf(ni->ni_macaddr));
sn->num_rates = ni->ni_rates.rs_nrates;
for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL;
sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate];
sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode;
sn->rates[x].shortPreambleRateCode =
rt->info[sn->rates[x].rix].rateCode |
rt->info[sn->rates[x].rix].shortPreamble;
DPRINTF(sc, " %d/%d", sn->rates[x].rate,
calc_usecs_unicast_packet(sc, 1600, sn->rates[x].rix,
0,0));
}
DPRINTF(sc, "%s\n", "");
/* set the visible bit-rate to the lowest one available */
ni->ni_txrate = 0;
sn->num_rates = ni->ni_rates.rs_nrates;
for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
int size = bin_to_size(y);
int ndx = 0;
sn->packets_sent[y] = 0;
sn->current_sample_ndx[y] = -1;
sn->last_sample_ndx[y] = 0;
for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
sn->stats[y][x].successive_failures = 0;
sn->stats[y][x].tries = 0;
sn->stats[y][x].total_packets = 0;
sn->stats[y][x].packets_acked = 0;
sn->stats[y][x].last_tx = 0;
sn->stats[y][x].perfect_tx_time =
calc_usecs_unicast_packet(sc, size,
sn->rates[x].rix,
0, 0);
sn->stats[y][x].average_tx_time = sn->stats[y][x].perfect_tx_time;
}
/* set the initial rate */
for (ndx = sn->num_rates-1; ndx > 0; ndx--) {
if (sn->rates[ndx].rate <= 72) {
break;
}
}
sn->current_rate[y] = ndx;
}
DPRINTF(sc, "%s: %s %d rates %d%sMbps (%dus)- %d%sMbps (%dus)\n",
__func__, ether_sprintf(ni->ni_macaddr),
sn->num_rates,
sn->rates[0].rate/2, sn->rates[0].rate % 0x1 ? ".5" : "",
sn->stats[1][0].perfect_tx_time,
sn->rates[sn->num_rates-1].rate/2,
sn->rates[sn->num_rates-1].rate % 0x1 ? ".5" : "",
sn->stats[1][sn->num_rates-1].perfect_tx_time
);
ni->ni_txrate = sn->current_rate[0];
#undef RATE
}
static void
rate_cb(void *arg, struct ieee80211_node *ni)
{
struct ath_softc *sc = arg;
ath_rate_newassoc(sc, ATH_NODE(ni), 1);
}
/*
* Reset the rate control state for each 802.11 state transition.
*/
void
ath_rate_newstate(struct ath_softc *sc, enum ieee80211_state state)
{
struct ieee80211com *ic = &sc->sc_ic;
if (state == IEEE80211_S_RUN) {
if (ic->ic_opmode != IEEE80211_M_STA) {
/*
* Sync rates for associated stations and neighbors.
*/
ieee80211_iterate_nodes(&ic->ic_sta, rate_cb, sc);
}
ath_rate_newassoc(sc, ATH_NODE(ic->ic_bss), 1);
}
}
static void
ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *osc)
{
int rc;
struct sysctllog **log = &sc->sc_sysctllog;
const struct sysctlnode *cnode, *rnode;
if ((rnode = ath_sysctl_instance(sc->sc_dev.dv_xname, log)) == NULL)
return;
/* XXX bounds check [0..100] */
if ((rc = SYSCTL_PFX_INT(osc->ath_, CTLFLAG_READWRITE, smoothing_rate,
"rate control: retry threshold to credit rate raise (%%)")) != 0)
goto err;
/* XXX bounds check [2..100] */
if ((rc = SYSCTL_PFX_INT(osc->ath_, CTLFLAG_READWRITE, sample_rate,
"rate control: # good periods before raising rate")) != 0)
goto err;
return;
err:
printf("%s: sysctl_createv failed, rc = %d\n", __func__, rc);
}
struct ath_ratectrl *
ath_rate_attach(struct ath_softc *sc)
{
struct sample_softc *osc;
DPRINTF(sc, "%s:\n", __func__);
osc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
if (osc == NULL)
return NULL;
osc->arc.arc_space = sizeof(struct sample_node);
osc->ath_smoothing_rate = 95; /* ewma percentage (out of 100) */
osc->ath_sample_rate = 10; /* send a different bit-rate 1/X packets */
ath_rate_sysctlattach(sc, osc);
return &osc->arc;
}
void
ath_rate_detach(struct ath_ratectrl *arc)
{
struct sample_softc *osc = (struct sample_softc *) arc;
free(osc, M_DEVBUF);
}
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