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freebsd-nq/sys/dev/ath/ath_rate/sample/sample.c

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/*-
* 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>
__FBSDID("$FreeBSD$");
/*
* John Bicket's SampleRate control algorithm.
*/
#include "opt_ath.h"
#include "opt_inet.h"
#include "opt_wlan.h"
#include "opt_ah.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/errno.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/if_arp.h>
#include <net/ethernet.h> /* XXX for ether_sprintf */
#include <net80211/ieee80211_var.h>
#include <net/bpf.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif
#include <dev/ath/if_athvar.h>
#include <dev/ath/ath_rate/sample/sample.h>
#include <dev/ath/ath_hal/ah_desc.h>
#include <dev/ath/ath_rate/sample/tx_schedules.h>
/*
* 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.
*/
static void ath_rate_ctl_reset(struct ath_softc *, struct ieee80211_node *);
static __inline int
size_to_bin(int size)
{
#if NUM_PACKET_SIZE_BINS > 1
if (size <= packet_size_bins[0])
return 0;
#endif
#if NUM_PACKET_SIZE_BINS > 2
if (size <= packet_size_bins[1])
return 1;
#endif
#if NUM_PACKET_SIZE_BINS > 3
if (size <= packet_size_bins[2])
return 2;
#endif
#if NUM_PACKET_SIZE_BINS > 4
#error "add support for more packet sizes"
#endif
return NUM_PACKET_SIZE_BINS-1;
}
void
ath_rate_node_init(struct ath_softc *sc, struct ath_node *an)
{
/* NB: assumed to be zero'd by caller */
}
void
ath_rate_node_cleanup(struct ath_softc *sc, struct ath_node *an)
{
}
static int
dot11rate(const HAL_RATE_TABLE *rt, int rix)
{
if (rix < 0)
return -1;
return rt->info[rix].phy == IEEE80211_T_HT ?
rt->info[rix].dot11Rate : (rt->info[rix].dot11Rate & IEEE80211_RATE_VAL) / 2;
}
static const char *
dot11rate_label(const HAL_RATE_TABLE *rt, int rix)
{
if (rix < 0)
return "";
return rt->info[rix].phy == IEEE80211_T_HT ? "MCS" : "Mb ";
}
/*
* Return the rix with the lowest average_tx_time,
* or -1 if all the average_tx_times are 0.
*/
static __inline int
pick_best_rate(struct ath_node *an, const HAL_RATE_TABLE *rt,
int size_bin, int require_acked_before)
{
struct sample_node *sn = ATH_NODE_SAMPLE(an);
int best_rate_rix, best_rate_tt, best_rate_pct;
uint64_t mask;
int rix, tt, pct;
best_rate_rix = 0;
best_rate_tt = 0;
best_rate_pct = 0;
for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
if ((mask & 1) == 0) /* not a supported rate */
continue;
/* Don't pick a non-HT rate for a HT node */
if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
(rt->info[rix].phy != IEEE80211_T_HT)) {
continue;
}
tt = sn->stats[size_bin][rix].average_tx_time;
if (tt <= 0 ||
(require_acked_before &&
!sn->stats[size_bin][rix].packets_acked))
continue;
/* Calculate percentage if possible */
if (sn->stats[size_bin][rix].total_packets > 0) {
pct = sn->stats[size_bin][rix].ewma_pct;
} else {
/* XXX for now, assume 95% ok */
pct = 95;
}
/* don't use a bit-rate that has been failing */
if (sn->stats[size_bin][rix].successive_failures > 3)
continue;
/*
* For HT, Don't use a bit rate that is much more
* lossy than the best.
*
* XXX this isn't optimal; it's just designed to
* eliminate rates that are going to be obviously
* worse.
*/
if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
if (best_rate_pct > (pct + 50))
continue;
}
/*
* For non-MCS rates, use the current average txtime for
* comparison.
*/
if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
if (best_rate_tt == 0 || tt <= best_rate_tt) {
best_rate_tt = tt;
best_rate_rix = rix;
best_rate_pct = pct;
}
}
/*
* Since 2 stream rates have slightly higher TX times,
* allow a little bit of leeway. This should later
* be abstracted out and properly handled.
*/
if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
if (best_rate_tt == 0 || (tt * 8 <= best_rate_tt * 10)) {
best_rate_tt = tt;
best_rate_rix = rix;
best_rate_pct = pct;
}
}
}
return (best_rate_tt ? best_rate_rix : -1);
}
/*
* Pick a good "random" bit-rate to sample other than the current one.
*/
static __inline int
pick_sample_rate(struct sample_softc *ssc , struct ath_node *an,
const HAL_RATE_TABLE *rt, int size_bin)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
struct sample_node *sn = ATH_NODE_SAMPLE(an);
int current_rix, rix;
unsigned current_tt;
uint64_t mask;
current_rix = sn->current_rix[size_bin];
if (current_rix < 0) {
/* no successes yet, send at the lowest bit-rate */
/* XXX should return MCS0 if HT */
return 0;
}
current_tt = sn->stats[size_bin][current_rix].average_tx_time;
rix = sn->last_sample_rix[size_bin]+1; /* next sample rate */
mask = sn->ratemask &~ ((uint64_t) 1<<current_rix);/* don't sample current rate */
while (mask != 0) {
if ((mask & ((uint64_t) 1<<rix)) == 0) { /* not a supported rate */
nextrate:
if (++rix >= rt->rateCount)
rix = 0;
continue;
}
/*
* The following code stops trying to sample
* non-MCS rates when speaking to an MCS node.
* However, at least for CCK rates in 2.4GHz mode,
* the non-MCS rates MAY actually provide better
* PER at the very far edge of reception.
*
* However! Until ath_rate_form_aggr() grows
* some logic to not form aggregates if the
* selected rate is non-MCS, this won't work.
*
* So don't disable this code until you've taught
* ath_rate_form_aggr() to drop out if any of
* the selected rates are non-MCS.
*/
#if 1
/* if the node is HT and the rate isn't HT, don't bother sample */
if ((an->an_node.ni_flags & IEEE80211_NODE_HT) &&
(rt->info[rix].phy != IEEE80211_T_HT)) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
#endif
/* this bit-rate is always worse than the current one */
if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
/* rarely sample bit-rates that fail a lot */
if (sn->stats[size_bin][rix].successive_failures > ssc->max_successive_failures &&
ticks - sn->stats[size_bin][rix].last_tx < ssc->stale_failure_timeout) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
/*
* For HT, only sample a few rates on either side of the
* current rix; there's quite likely a lot of them.
*/
if (an->an_node.ni_flags & IEEE80211_NODE_HT) {
if (rix < (current_rix - 3) ||
rix > (current_rix + 3)) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
}
/* Don't sample more than 2 rates higher for rates > 11M for non-HT rates */
if (! (an->an_node.ni_flags & IEEE80211_NODE_HT)) {
if (DOT11RATE(rix) > 2*11 && rix > current_rix + 2) {
mask &= ~((uint64_t) 1<<rix);
goto nextrate;
}
}
sn->last_sample_rix[size_bin] = rix;
return rix;
}
return current_rix;
#undef DOT11RATE
#undef MCS
}
static int
ath_rate_get_static_rix(struct ath_softc *sc, const struct ieee80211_node *ni)
{
#define RATE(_ix) (ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)
#define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
const struct ieee80211_txparam *tp = ni->ni_txparms;
int srate;
/* Check MCS rates */
for (srate = ni->ni_htrates.rs_nrates - 1; srate >= 0; srate--) {
if (MCS(srate) == tp->ucastrate)
return sc->sc_rixmap[tp->ucastrate];
}
/* Check legacy rates */
for (srate = ni->ni_rates.rs_nrates - 1; srate >= 0; srate--) {
if (RATE(srate) == tp->ucastrate)
return sc->sc_rixmap[tp->ucastrate];
}
return -1;
#undef RATE
#undef DOT11RATE
#undef MCS
}
static void
ath_rate_update_static_rix(struct ath_softc *sc, struct ieee80211_node *ni)
{
struct ath_node *an = ATH_NODE(ni);
const struct ieee80211_txparam *tp = ni->ni_txparms;
struct sample_node *sn = ATH_NODE_SAMPLE(an);
if (tp != NULL && tp->ucastrate != IEEE80211_FIXED_RATE_NONE) {
/*
* A fixed rate is to be used; ucastrate is the IEEE code
* for this rate (sans basic bit). Check this against the
* negotiated rate set for the node. Note the fixed rate
* may not be available for various reasons so we only
* setup the static rate index if the lookup is successful.
*/
sn->static_rix = ath_rate_get_static_rix(sc, ni);
} else {
sn->static_rix = -1;
}
}
/*
* Pick a non-HT rate to begin using.
*/
static int
ath_rate_pick_seed_rate_legacy(struct ath_softc *sc, struct ath_node *an,
int frameLen)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
#define RATE(ix) (DOT11RATE(ix) / 2)
int rix = -1;
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct sample_node *sn = ATH_NODE_SAMPLE(an);
const int size_bin = size_to_bin(frameLen);
/* no packet has been sent successfully yet */
for (rix = rt->rateCount-1; rix > 0; rix--) {
if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
continue;
/* Skip HT rates */
if (rt->info[rix].phy == IEEE80211_T_HT)
continue;
/*
* Pick the highest rate <= 36 Mbps
* that hasn't failed.
*/
if (DOT11RATE(rix) <= 72 &&
sn->stats[size_bin][rix].successive_failures == 0) {
break;
}
}
return rix;
#undef RATE
#undef MCS
#undef DOT11RATE
}
/*
* Pick a HT rate to begin using.
*
* Don't use any non-HT rates; only consider HT rates.
*/
static int
ath_rate_pick_seed_rate_ht(struct ath_softc *sc, struct ath_node *an,
int frameLen)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
#define RATE(ix) (DOT11RATE(ix) / 2)
int rix = -1, ht_rix = -1;
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct sample_node *sn = ATH_NODE_SAMPLE(an);
const int size_bin = size_to_bin(frameLen);
/* no packet has been sent successfully yet */
for (rix = rt->rateCount-1; rix > 0; rix--) {
/* Skip rates we can't use */
if ((sn->ratemask & ((uint64_t) 1<<rix)) == 0)
continue;
/* Keep a copy of the last seen HT rate index */
if (rt->info[rix].phy == IEEE80211_T_HT)
ht_rix = rix;
/* Skip non-HT rates */
if (rt->info[rix].phy != IEEE80211_T_HT)
continue;
/*
* Pick a medium-speed rate regardless of stream count
* which has not seen any failures. Higher rates may fail;
* we'll try them later.
*/
if (((MCS(rix) & 0x7) <= 4) &&
sn->stats[size_bin][rix].successive_failures == 0) {
break;
}
}
/*
* If all the MCS rates have successive failures, rix should be
* > 0; otherwise use the lowest MCS rix (hopefully MCS 0.)
*/
return MAX(rix, ht_rix);
#undef RATE
#undef MCS
#undef DOT11RATE
}
void
ath_rate_findrate(struct ath_softc *sc, struct ath_node *an,
int shortPreamble, size_t frameLen,
u_int8_t *rix0, int *try0, u_int8_t *txrate)
{
#define DOT11RATE(ix) (rt->info[ix].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(ix) (rt->info[ix].dot11Rate | IEEE80211_RATE_MCS)
#define RATE(ix) (DOT11RATE(ix) / 2)
struct sample_node *sn = ATH_NODE_SAMPLE(an);
struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
struct ifnet *ifp = sc->sc_ifp;
struct ieee80211com *ic = ifp->if_l2com;
const HAL_RATE_TABLE *rt = sc->sc_currates;
const int size_bin = size_to_bin(frameLen);
int rix, mrr, best_rix, change_rates;
unsigned average_tx_time;
ath_rate_update_static_rix(sc, &an->an_node);
if (sn->currates != sc->sc_currates) {
device_printf(sc->sc_dev, "%s: currates != sc_currates!\n",
__func__);
rix = 0;
*try0 = ATH_TXMAXTRY;
goto done;
}
if (sn->static_rix != -1) {
rix = sn->static_rix;
*try0 = ATH_TXMAXTRY;
goto done;
}
mrr = sc->sc_mrretry;
/* XXX check HT protmode too */
if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
mrr = 0;
best_rix = pick_best_rate(an, rt, size_bin, !mrr);
if (best_rix >= 0) {
average_tx_time = sn->stats[size_bin][best_rix].average_tx_time;
} else {
average_tx_time = 0;
}
/*
* Limit the time measuring the performance of other tx
* rates to sample_rate% of the total transmission time.
*/
if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin]*ssc->sample_rate/100)) {
rix = pick_sample_rate(ssc, an, rt, size_bin);
IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
&an->an_node, "att %d sample_tt %d size %u sample rate %d %s current rate %d %s",
average_tx_time,
sn->sample_tt[size_bin],
bin_to_size(size_bin),
dot11rate(rt, rix),
dot11rate_label(rt, rix),
dot11rate(rt, sn->current_rix[size_bin]),
dot11rate_label(rt, sn->current_rix[size_bin]));
if (rix != sn->current_rix[size_bin]) {
sn->current_sample_rix[size_bin] = rix;
} else {
sn->current_sample_rix[size_bin] = -1;
}
sn->packets_since_sample[size_bin] = 0;
} else {
change_rates = 0;
if (!sn->packets_sent[size_bin] || best_rix == -1) {
/* no packet has been sent successfully yet */
change_rates = 1;
if (an->an_node.ni_flags & IEEE80211_NODE_HT)
best_rix =
ath_rate_pick_seed_rate_ht(sc, an, frameLen);
else
best_rix =
ath_rate_pick_seed_rate_legacy(sc, an, frameLen);
} else if (sn->packets_sent[size_bin] < 20) {
/* let the bit-rate switch quickly during the first few packets */
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL, &an->an_node,
"%s: switching quickly..", __func__);
change_rates = 1;
} else if (ticks - ssc->min_switch > sn->ticks_since_switch[size_bin]) {
/* min_switch seconds have gone by */
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL, &an->an_node,
"%s: min_switch %d > ticks_since_switch %d..",
__func__, ticks - ssc->min_switch, sn->ticks_since_switch[size_bin]);
change_rates = 1;
} else if ((! (an->an_node.ni_flags & IEEE80211_NODE_HT)) &&
(2*average_tx_time < sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time)) {
/* the current bit-rate is twice as slow as the best one */
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL, &an->an_node,
"%s: 2x att (= %d) < cur_rix att %d",
__func__,
2 * average_tx_time, sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time);
change_rates = 1;
} else if ((an->an_node.ni_flags & IEEE80211_NODE_HT)) {
int cur_rix = sn->current_rix[size_bin];
int cur_att = sn->stats[size_bin][cur_rix].average_tx_time;
/*
* If the node is HT, upgrade it if the MCS rate is
* higher and the average tx time is within 20% of
* the current rate. It can fail a little.
*
* This is likely not optimal!
*/
#if 0
printf("cur rix/att %x/%d, best rix/att %x/%d\n",
MCS(cur_rix), cur_att, MCS(best_rix), average_tx_time);
#endif
if ((MCS(best_rix) > MCS(cur_rix)) &&
(average_tx_time * 8) <= (cur_att * 10)) {
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL, &an->an_node,
"%s: HT: best_rix 0x%d > cur_rix 0x%x, average_tx_time %d, cur_att %d",
__func__,
MCS(best_rix), MCS(cur_rix), average_tx_time, cur_att);
change_rates = 1;
}
}
sn->packets_since_sample[size_bin]++;
if (change_rates) {
if (best_rix != sn->current_rix[size_bin]) {
IEEE80211_NOTE(an->an_node.ni_vap,
IEEE80211_MSG_RATECTL,
&an->an_node,
"%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
__func__,
bin_to_size(size_bin),
RATE(sn->current_rix[size_bin]),
sn->stats[size_bin][sn->current_rix[size_bin]].average_tx_time,
sn->stats[size_bin][sn->current_rix[size_bin]].perfect_tx_time,
RATE(best_rix),
sn->stats[size_bin][best_rix].average_tx_time,
sn->stats[size_bin][best_rix].perfect_tx_time,
sn->packets_since_switch[size_bin],
mrr);
}
sn->packets_since_switch[size_bin] = 0;
sn->current_rix[size_bin] = best_rix;
sn->ticks_since_switch[size_bin] = ticks;
/*
* Set the visible txrate for this node.
*/
an->an_node.ni_txrate = (rt->info[best_rix].phy == IEEE80211_T_HT) ? MCS(best_rix) : DOT11RATE(best_rix);
}
rix = sn->current_rix[size_bin];
sn->packets_since_switch[size_bin]++;
}
*try0 = mrr ? sn->sched[rix].t0 : ATH_TXMAXTRY;
done:
/*
* This bug totally sucks and should be fixed.
*
* For now though, let's not panic, so we can start to figure
* out how to better reproduce it.
*/
if (rix < 0 || rix >= rt->rateCount) {
printf("%s: ERROR: rix %d out of bounds (rateCount=%d)\n",
__func__,
rix,
rt->rateCount);
rix = 0; /* XXX just default for now */
}
KASSERT(rix >= 0 && rix < rt->rateCount, ("rix is %d", rix));
*rix0 = rix;
*txrate = rt->info[rix].rateCode
| (shortPreamble ? rt->info[rix].shortPreamble : 0);
sn->packets_sent[size_bin]++;
#undef DOT11RATE
#undef MCS
#undef RATE
}
/*
* Get the TX rates. Don't fiddle with short preamble flags for them;
* the caller can do that.
*/
void
ath_rate_getxtxrates(struct ath_softc *sc, struct ath_node *an,
uint8_t rix0, struct ath_rc_series *rc)
{
struct sample_node *sn = ATH_NODE_SAMPLE(an);
const struct txschedule *sched = &sn->sched[rix0];
KASSERT(rix0 == sched->r0, ("rix0 (%x) != sched->r0 (%x)!\n",
rix0, sched->r0));
rc[0].flags = rc[1].flags = rc[2].flags = rc[3].flags = 0;
rc[0].rix = sched->r0;
rc[1].rix = sched->r1;
rc[2].rix = sched->r2;
rc[3].rix = sched->r3;
rc[0].tries = sched->t0;
rc[1].tries = sched->t1;
rc[2].tries = sched->t2;
rc[3].tries = sched->t3;
}
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);
const struct txschedule *sched = &sn->sched[rix];
const HAL_RATE_TABLE *rt = sc->sc_currates;
uint8_t rix1, s1code, rix2, s2code, rix3, s3code;
/* XXX precalculate short preamble tables */
rix1 = sched->r1;
s1code = rt->info[rix1].rateCode
| (shortPreamble ? rt->info[rix1].shortPreamble : 0);
rix2 = sched->r2;
s2code = rt->info[rix2].rateCode
| (shortPreamble ? rt->info[rix2].shortPreamble : 0);
rix3 = sched->r3;
s3code = rt->info[rix3].rateCode
| (shortPreamble ? rt->info[rix3].shortPreamble : 0);
ath_hal_setupxtxdesc(sc->sc_ah, ds,
s1code, sched->t1, /* series 1 */
s2code, sched->t2, /* series 2 */
s3code, sched->t3); /* series 3 */
}
static void
update_stats(struct ath_softc *sc, struct ath_node *an,
int frame_size,
int rix0, int tries0,
int rix1, int tries1,
int rix2, int tries2,
int rix3, int tries3,
int short_tries, int tries, int status,
int nframes, int nbad)
{
struct sample_node *sn = ATH_NODE_SAMPLE(an);
struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
#ifdef IEEE80211_DEBUG
const HAL_RATE_TABLE *rt = sc->sc_currates;
#endif
const int size_bin = size_to_bin(frame_size);
const int size = bin_to_size(size_bin);
int tt, tries_so_far;
int is_ht40 = (an->an_node.ni_chw == 40);
int pct;
if (!IS_RATE_DEFINED(sn, rix0))
return;
tt = calc_usecs_unicast_packet(sc, size, rix0, short_tries,
MIN(tries0, tries) - 1, is_ht40);
tries_so_far = tries0;
if (tries1 && tries_so_far < tries) {
if (!IS_RATE_DEFINED(sn, rix1))
return;
tt += calc_usecs_unicast_packet(sc, size, rix1, short_tries,
MIN(tries1 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
tries_so_far += tries1;
}
if (tries2 && tries_so_far < tries) {
if (!IS_RATE_DEFINED(sn, rix2))
return;
tt += calc_usecs_unicast_packet(sc, size, rix2, short_tries,
MIN(tries2 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
tries_so_far += tries2;
}
if (tries3 && tries_so_far < tries) {
if (!IS_RATE_DEFINED(sn, rix3))
return;
tt += calc_usecs_unicast_packet(sc, size, rix3, short_tries,
MIN(tries3 + tries_so_far, tries) - tries_so_far - 1, is_ht40);
}
if (sn->stats[size_bin][rix0].total_packets < ssc->smoothing_minpackets) {
/* just average the first few packets */
int avg_tx = sn->stats[size_bin][rix0].average_tx_time;
int packets = sn->stats[size_bin][rix0].total_packets;
sn->stats[size_bin][rix0].average_tx_time = (tt+(avg_tx*packets))/(packets+nframes);
} else {
/* use a ewma */
sn->stats[size_bin][rix0].average_tx_time =
((sn->stats[size_bin][rix0].average_tx_time * ssc->smoothing_rate) +
(tt * (100 - ssc->smoothing_rate))) / 100;
}
/*
* XXX Don't mark the higher bit rates as also having failed; as this
* unfortunately stops those rates from being tasted when trying to
* TX. This happens with 11n aggregation.
*/
if (nframes == nbad) {
#if 0
int y;
#endif
sn->stats[size_bin][rix0].successive_failures += nbad;
#if 0
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
* bit-rate then a larger one will also.
*/
sn->stats[y][rix0].successive_failures += nbad;
sn->stats[y][rix0].last_tx = ticks;
sn->stats[y][rix0].tries += tries;
sn->stats[y][rix0].total_packets += nframes;
}
#endif
} else {
sn->stats[size_bin][rix0].packets_acked += (nframes - nbad);
sn->stats[size_bin][rix0].successive_failures = 0;
}
sn->stats[size_bin][rix0].tries += tries;
sn->stats[size_bin][rix0].last_tx = ticks;
sn->stats[size_bin][rix0].total_packets += nframes;
/* update EWMA for this rix */
/* Calculate percentage based on current rate */
if (nframes == 0)
nframes = nbad = 1;
pct = ((nframes - nbad) * 1000) / nframes;
if (sn->stats[size_bin][rix0].total_packets <
ssc->smoothing_minpackets) {
/* just average the first few packets */
int a_pct = (sn->stats[size_bin][rix0].packets_acked * 1000) /
(sn->stats[size_bin][rix0].total_packets);
sn->stats[size_bin][rix0].ewma_pct = a_pct;
} else {
/* use a ewma */
sn->stats[size_bin][rix0].ewma_pct =
((sn->stats[size_bin][rix0].ewma_pct * ssc->smoothing_rate) +
(pct * (100 - ssc->smoothing_rate))) / 100;
}
if (rix0 == sn->current_sample_rix[size_bin]) {
IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
&an->an_node,
"%s: size %d %s sample rate %d %s tries (%d/%d) tt %d avg_tt (%d/%d) nfrm %d nbad %d",
__func__,
size,
status ? "FAIL" : "OK",
dot11rate(rt, rix0),
dot11rate_label(rt, rix0),
short_tries, tries, tt,
sn->stats[size_bin][rix0].average_tx_time,
sn->stats[size_bin][rix0].perfect_tx_time,
nframes, nbad);
sn->sample_tt[size_bin] = tt;
sn->current_sample_rix[size_bin] = -1;
}
}
static void
badrate(struct ath_softc *sc, int series, int hwrate, int tries, int status)
{
device_printf(sc->sc_dev,
"bad series%d hwrate 0x%x, tries %u ts_status 0x%x\n",
series, hwrate, tries, status);
}
void
ath_rate_tx_complete(struct ath_softc *sc, struct ath_node *an,
const struct ath_rc_series *rc, const struct ath_tx_status *ts,
int frame_size, int nframes, int nbad)
{
struct ifnet *ifp = sc->sc_ifp;
struct ieee80211com *ic = ifp->if_l2com;
struct sample_node *sn = ATH_NODE_SAMPLE(an);
int final_rix, short_tries, long_tries;
const HAL_RATE_TABLE *rt = sc->sc_currates;
int status = ts->ts_status;
int mrr;
final_rix = rt->rateCodeToIndex[ts->ts_rate];
short_tries = ts->ts_shortretry;
long_tries = ts->ts_longretry + 1;
if (nframes == 0) {
device_printf(sc->sc_dev, "%s: nframes=0?\n", __func__);
return;
}
if (frame_size == 0) /* NB: should not happen */
frame_size = 1500;
if (sn->ratemask == 0) {
IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
&an->an_node,
"%s: size %d %s rate/try %d/%d no rates yet",
__func__,
bin_to_size(size_to_bin(frame_size)),
status ? "FAIL" : "OK",
short_tries, long_tries);
return;
}
mrr = sc->sc_mrretry;
/* XXX check HT protmode too */
if (mrr && (ic->ic_flags & IEEE80211_F_USEPROT && !sc->sc_mrrprot))
mrr = 0;
if (!mrr || ts->ts_finaltsi == 0) {
if (!IS_RATE_DEFINED(sn, final_rix)) {
device_printf(sc->sc_dev,
"%s: ts_rate=%d ts_finaltsi=%d, final_rix=%d\n",
__func__, ts->ts_rate, ts->ts_finaltsi, final_rix);
badrate(sc, 0, ts->ts_rate, long_tries, status);
return;
}
/*
* Only one rate was used; optimize work.
*/
IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
&an->an_node, "%s: size %d (%d bytes) %s rate/short/long %d %s/%d/%d nframes/nbad [%d/%d]",
__func__,
bin_to_size(size_to_bin(frame_size)),
frame_size,
status ? "FAIL" : "OK",
dot11rate(rt, final_rix), dot11rate_label(rt, final_rix),
short_tries, long_tries, nframes, nbad);
update_stats(sc, an, frame_size,
final_rix, long_tries,
0, 0,
0, 0,
0, 0,
short_tries, long_tries, status,
nframes, nbad);
} else {
int finalTSIdx = ts->ts_finaltsi;
int i;
/*
* Process intermediate rates that failed.
*/
IEEE80211_NOTE(an->an_node.ni_vap, IEEE80211_MSG_RATECTL,
&an->an_node,
"%s: size %d (%d bytes) finaltsidx %d short %d long %d %s rate/try [%d %s/%d %d %s/%d %d %s/%d %d %s/%d] nframes/nbad [%d/%d]",
__func__,
bin_to_size(size_to_bin(frame_size)),
frame_size,
finalTSIdx,
short_tries,
long_tries,
status ? "FAIL" : "OK",
dot11rate(rt, rc[0].rix),
dot11rate_label(rt, rc[0].rix), rc[0].tries,
dot11rate(rt, rc[1].rix),
dot11rate_label(rt, rc[1].rix), rc[1].tries,
dot11rate(rt, rc[2].rix),
dot11rate_label(rt, rc[2].rix), rc[2].tries,
dot11rate(rt, rc[3].rix),
dot11rate_label(rt, rc[3].rix), rc[3].tries,
nframes, nbad);
for (i = 0; i < 4; i++) {
if (rc[i].tries && !IS_RATE_DEFINED(sn, rc[i].rix))
badrate(sc, 0, rc[i].ratecode, rc[i].tries,
status);
}
/*
* NB: series > 0 are not penalized for failure
* based on the try counts under the assumption
* that losses are often bursty and since we
* sample higher rates 1 try at a time doing so
* may unfairly penalize them.
*/
if (rc[0].tries) {
update_stats(sc, an, frame_size,
rc[0].rix, rc[0].tries,
rc[1].rix, rc[1].tries,
rc[2].rix, rc[2].tries,
rc[3].rix, rc[3].tries,
short_tries, long_tries,
long_tries > rc[0].tries,
nframes, nbad);
long_tries -= rc[0].tries;
}
if (rc[1].tries && finalTSIdx > 0) {
update_stats(sc, an, frame_size,
rc[1].rix, rc[1].tries,
rc[2].rix, rc[2].tries,
rc[3].rix, rc[3].tries,
0, 0,
short_tries, long_tries,
status,
nframes, nbad);
long_tries -= rc[1].tries;
}
if (rc[2].tries && finalTSIdx > 1) {
update_stats(sc, an, frame_size,
rc[2].rix, rc[2].tries,
rc[3].rix, rc[3].tries,
0, 0,
0, 0,
short_tries, long_tries,
status,
nframes, nbad);
long_tries -= rc[2].tries;
}
if (rc[3].tries && finalTSIdx > 2) {
update_stats(sc, an, frame_size,
rc[3].rix, rc[3].tries,
0, 0,
0, 0,
0, 0,
short_tries, long_tries,
status,
nframes, nbad);
}
}
}
void
ath_rate_newassoc(struct ath_softc *sc, struct ath_node *an, int isnew)
{
if (isnew)
ath_rate_ctl_reset(sc, &an->an_node);
}
static const struct txschedule *mrr_schedules[IEEE80211_MODE_MAX+2] = {
NULL, /* IEEE80211_MODE_AUTO */
series_11a, /* IEEE80211_MODE_11A */
series_11g, /* IEEE80211_MODE_11B */
series_11g, /* IEEE80211_MODE_11G */
NULL, /* IEEE80211_MODE_FH */
series_11a, /* IEEE80211_MODE_TURBO_A */
series_11g, /* IEEE80211_MODE_TURBO_G */
series_11a, /* IEEE80211_MODE_STURBO_A */
series_11na, /* IEEE80211_MODE_11NA */
series_11ng, /* IEEE80211_MODE_11NG */
series_half, /* IEEE80211_MODE_HALF */
series_quarter, /* IEEE80211_MODE_QUARTER */
};
/*
* 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)
#define DOT11RATE(_ix) (rt->info[(_ix)].dot11Rate & IEEE80211_RATE_VAL)
#define MCS(_ix) (ni->ni_htrates.rs_rates[_ix] | IEEE80211_RATE_MCS)
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, rix;
KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
KASSERT(sc->sc_curmode < IEEE80211_MODE_MAX+2,
("curmode %u", sc->sc_curmode));
sn->sched = mrr_schedules[sc->sc_curmode];
KASSERT(sn->sched != NULL,
("no mrr schedule for mode %u", sc->sc_curmode));
sn->static_rix = -1;
ath_rate_update_static_rix(sc, ni);
sn->currates = sc->sc_currates;
/*
* Construct a bitmask of usable rates. This has all
* negotiated rates minus those marked by the hal as
* to be ignored for doing rate control.
*/
sn->ratemask = 0;
/* MCS rates */
if (ni->ni_flags & IEEE80211_NODE_HT) {
for (x = 0; x < ni->ni_htrates.rs_nrates; x++) {
rix = sc->sc_rixmap[MCS(x)];
if (rix == 0xff)
continue;
/* skip rates marked broken by hal */
if (!rt->info[rix].valid)
continue;
KASSERT(rix < SAMPLE_MAXRATES,
("mcs %u has rix %d", MCS(x), rix));
sn->ratemask |= (uint64_t) 1<<rix;
}
}
/* Legacy rates */
for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
rix = sc->sc_rixmap[RATE(x)];
if (rix == 0xff)
continue;
/* skip rates marked broken by hal */
if (!rt->info[rix].valid)
continue;
KASSERT(rix < SAMPLE_MAXRATES,
("rate %u has rix %d", RATE(x), rix));
sn->ratemask |= (uint64_t) 1<<rix;
}
#ifdef IEEE80211_DEBUG
if (ieee80211_msg(ni->ni_vap, IEEE80211_MSG_RATECTL)) {
uint64_t mask;
ieee80211_note(ni->ni_vap, "[%6D] %s: size 1600 rate/tt",
ni->ni_macaddr, ":", __func__);
for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
if ((mask & 1) == 0)
continue;
printf(" %d %s/%d", dot11rate(rt, rix), dot11rate_label(rt, rix),
calc_usecs_unicast_packet(sc, 1600, rix, 0,0,
(ni->ni_chw == 40)));
}
printf("\n");
}
#endif
for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
int size = bin_to_size(y);
uint64_t mask;
sn->packets_sent[y] = 0;
sn->current_sample_rix[y] = -1;
sn->last_sample_rix[y] = 0;
/* XXX start with first valid rate */
sn->current_rix[y] = ffs(sn->ratemask)-1;
/*
* Initialize the statistics buckets; these are
* indexed by the rate code index.
*/
for (rix = 0, mask = sn->ratemask; mask != 0; rix++, mask >>= 1) {
if ((mask & 1) == 0) /* not a valid rate */
continue;
sn->stats[y][rix].successive_failures = 0;
sn->stats[y][rix].tries = 0;
sn->stats[y][rix].total_packets = 0;
sn->stats[y][rix].packets_acked = 0;
sn->stats[y][rix].last_tx = 0;
sn->stats[y][rix].ewma_pct = 0;
sn->stats[y][rix].perfect_tx_time =
calc_usecs_unicast_packet(sc, size, rix, 0, 0,
(ni->ni_chw == 40));
sn->stats[y][rix].average_tx_time =
sn->stats[y][rix].perfect_tx_time;
}
}
#if 0
/* XXX 0, num_rates-1 are wrong */
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"%s: %d rates %d%sMbps (%dus)- %d%sMbps (%dus)", __func__,
sn->num_rates,
DOT11RATE(0)/2, DOT11RATE(0) % 1 ? ".5" : "",
sn->stats[1][0].perfect_tx_time,
DOT11RATE(sn->num_rates-1)/2, DOT11RATE(sn->num_rates-1) % 1 ? ".5" : "",
sn->stats[1][sn->num_rates-1].perfect_tx_time
);
#endif
/* set the visible bit-rate */
if (sn->static_rix != -1)
ni->ni_txrate = DOT11RATE(sn->static_rix);
else
ni->ni_txrate = RATE(0);
#undef RATE
#undef DOT11RATE
}
/*
* Fetch the statistics for the given node.
*
* The ieee80211 node must be referenced and unlocked, however the ath_node
* must be locked.
*
* The main difference here is that we convert the rate indexes
* to 802.11 rates, or the userland output won't make much sense
* as it has no access to the rix table.
*/
int
ath_rate_fetch_node_stats(struct ath_softc *sc, struct ath_node *an,
struct ath_rateioctl *rs)
{
struct sample_node *sn = ATH_NODE_SAMPLE(an);
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct ath_rateioctl_tlv av;
struct ath_rateioctl_rt *tv;
int y;
int o = 0;
ATH_NODE_LOCK_ASSERT(an);
/*
* Ensure there's enough space for the statistics.
*/
if (rs->len <
sizeof(struct ath_rateioctl_tlv) +
sizeof(struct ath_rateioctl_rt) +
sizeof(struct ath_rateioctl_tlv) +
sizeof(struct sample_node)) {
device_printf(sc->sc_dev, "%s: len=%d, too short\n",
__func__,
rs->len);
return (EINVAL);
}
/*
* Take a temporary copy of the sample node state so we can
* modify it before we copy it.
*/
tv = malloc(sizeof(struct ath_rateioctl_rt), M_TEMP,
M_NOWAIT | M_ZERO);
if (tv == NULL) {
return (ENOMEM);
}
/*
* Populate the rate table mapping TLV.
*/
tv->nentries = rt->rateCount;
for (y = 0; y < rt->rateCount; y++) {
tv->ratecode[y] = rt->info[y].dot11Rate & IEEE80211_RATE_VAL;
if (rt->info[y].phy == IEEE80211_T_HT)
tv->ratecode[y] |= IEEE80211_RATE_MCS;
}
o = 0;
/*
* First TLV - rate code mapping
*/
av.tlv_id = ATH_RATE_TLV_RATETABLE;
av.tlv_len = sizeof(struct ath_rateioctl_rt);
copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
o += sizeof(struct ath_rateioctl_tlv);
copyout(tv, rs->buf + o, sizeof(struct ath_rateioctl_rt));
o += sizeof(struct ath_rateioctl_rt);
/*
* Second TLV - sample node statistics
*/
av.tlv_id = ATH_RATE_TLV_SAMPLENODE;
av.tlv_len = sizeof(struct sample_node);
copyout(&av, rs->buf + o, sizeof(struct ath_rateioctl_tlv));
o += sizeof(struct ath_rateioctl_tlv);
/*
* Copy the statistics over to the provided buffer.
*/
copyout(sn, rs->buf + o, sizeof(struct sample_node));
o += sizeof(struct sample_node);
free(tv, M_TEMP);
return (0);
}
static void
sample_stats(void *arg, struct ieee80211_node *ni)
{
struct ath_softc *sc = arg;
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct sample_node *sn = ATH_NODE_SAMPLE(ATH_NODE(ni));
uint64_t mask;
int rix, y;
printf("\n[%s] refcnt %d static_rix (%d %s) ratemask 0x%jx\n",
ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni),
dot11rate(rt, sn->static_rix),
dot11rate_label(rt, sn->static_rix),
(uintmax_t)sn->ratemask);
for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
printf("[%4u] cur rix %d (%d %s) since switch: packets %d ticks %u\n",
bin_to_size(y), sn->current_rix[y],
dot11rate(rt, sn->current_rix[y]),
dot11rate_label(rt, sn->current_rix[y]),
sn->packets_since_switch[y], sn->ticks_since_switch[y]);
printf("[%4u] last sample (%d %s) cur sample (%d %s) packets sent %d\n",
bin_to_size(y),
dot11rate(rt, sn->last_sample_rix[y]),
dot11rate_label(rt, sn->last_sample_rix[y]),
dot11rate(rt, sn->current_sample_rix[y]),
dot11rate_label(rt, sn->current_sample_rix[y]),
sn->packets_sent[y]);
printf("[%4u] packets since sample %d sample tt %u\n",
bin_to_size(y), sn->packets_since_sample[y],
sn->sample_tt[y]);
}
for (mask = sn->ratemask, rix = 0; mask != 0; mask >>= 1, rix++) {
if ((mask & 1) == 0)
continue;
for (y = 0; y < NUM_PACKET_SIZE_BINS; y++) {
if (sn->stats[y][rix].total_packets == 0)
continue;
printf("[%2u %s:%4u] %8ju:%-8ju (%3d%%) (EWMA %3d.%1d%%) T %8ju F %4d avg %5u last %u\n",
dot11rate(rt, rix), dot11rate_label(rt, rix),
bin_to_size(y),
(uintmax_t) sn->stats[y][rix].total_packets,
(uintmax_t) sn->stats[y][rix].packets_acked,
(int) ((sn->stats[y][rix].packets_acked * 100ULL) /
sn->stats[y][rix].total_packets),
sn->stats[y][rix].ewma_pct / 10,
sn->stats[y][rix].ewma_pct % 10,
(uintmax_t) sn->stats[y][rix].tries,
sn->stats[y][rix].successive_failures,
sn->stats[y][rix].average_tx_time,
ticks - sn->stats[y][rix].last_tx);
}
}
}
static int
ath_rate_sysctl_stats(SYSCTL_HANDLER_ARGS)
{
struct ath_softc *sc = arg1;
struct ifnet *ifp = sc->sc_ifp;
struct ieee80211com *ic = ifp->if_l2com;
int error, v;
v = 0;
error = sysctl_handle_int(oidp, &v, 0, req);
if (error || !req->newptr)
return error;
ieee80211_iterate_nodes(&ic->ic_sta, sample_stats, sc);
return 0;
}
static int
ath_rate_sysctl_smoothing_rate(SYSCTL_HANDLER_ARGS)
{
struct sample_softc *ssc = arg1;
int rate, error;
rate = ssc->smoothing_rate;
error = sysctl_handle_int(oidp, &rate, 0, req);
if (error || !req->newptr)
return error;
if (!(0 <= rate && rate < 100))
return EINVAL;
ssc->smoothing_rate = rate;
ssc->smoothing_minpackets = 100 / (100 - rate);
return 0;
}
static int
ath_rate_sysctl_sample_rate(SYSCTL_HANDLER_ARGS)
{
struct sample_softc *ssc = arg1;
int rate, error;
rate = ssc->sample_rate;
error = sysctl_handle_int(oidp, &rate, 0, req);
if (error || !req->newptr)
return error;
if (!(2 <= rate && rate <= 100))
return EINVAL;
ssc->sample_rate = rate;
return 0;
}
static void
ath_rate_sysctlattach(struct ath_softc *sc, struct sample_softc *ssc)
{
struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"smoothing_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
ath_rate_sysctl_smoothing_rate, "I",
"sample: smoothing rate for avg tx time (%%)");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"sample_rate", CTLTYPE_INT | CTLFLAG_RW, ssc, 0,
ath_rate_sysctl_sample_rate, "I",
"sample: percent air time devoted to sampling new rates (%%)");
/* XXX max_successive_failures, stale_failure_timeout, min_switch */
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"sample_stats", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
ath_rate_sysctl_stats, "I", "sample: print statistics");
}
struct ath_ratectrl *
ath_rate_attach(struct ath_softc *sc)
{
struct sample_softc *ssc;
ssc = malloc(sizeof(struct sample_softc), M_DEVBUF, M_NOWAIT|M_ZERO);
if (ssc == NULL)
return NULL;
ssc->arc.arc_space = sizeof(struct sample_node);
ssc->smoothing_rate = 75; /* ewma percentage ([0..99]) */
ssc->smoothing_minpackets = 100 / (100 - ssc->smoothing_rate);
ssc->sample_rate = 10; /* %time to try diff tx rates */
ssc->max_successive_failures = 3; /* threshold for rate sampling*/
ssc->stale_failure_timeout = 10 * hz; /* 10 seconds */
ssc->min_switch = hz; /* 1 second */
ath_rate_sysctlattach(sc, ssc);
return &ssc->arc;
}
void
ath_rate_detach(struct ath_ratectrl *arc)
{
struct sample_softc *ssc = (struct sample_softc *) arc;
free(ssc, M_DEVBUF);
}
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