freebsd-dev/sys/net80211/ieee80211_amrr.c
Adrian Chadd ebb1240823 After much toying around with this AMRR initial rate stuff,
I've decided that for 11n rates it's best to start (very) low and work
our way up.

So, from now on, the initial rate for AMRR 11n is MCS4.
It doesn't try MCS12 or MCS20 - at low signal strengths those don't
work very well at all.

AMRR will step the rate control up over time if things work out better.

Tested:

* Intel 5100
* Intel 5300 (using local diffs to test out 3x3 stream support)
2014-08-20 09:10:03 +00:00

412 lines
12 KiB
C

/* $OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $ */
/*-
* Copyright (c) 2010 Rui Paulo <rpaulo@FreeBSD.org>
* Copyright (c) 2006
* Damien Bergamini <damien.bergamini@free.fr>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*-
* Naive implementation of the Adaptive Multi Rate Retry algorithm:
*
* "IEEE 802.11 Rate Adaptation: A Practical Approach"
* Mathieu Lacage, Hossein Manshaei, Thierry Turletti
* INRIA Sophia - Projet Planete
* http://www-sop.inria.fr/rapports/sophia/RR-5208.html
*/
#include "opt_wlan.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/ethernet.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_ht.h>
#include <net80211/ieee80211_amrr.h>
#include <net80211/ieee80211_ratectl.h>
#define is_success(amn) \
((amn)->amn_retrycnt < (amn)->amn_txcnt / 10)
#define is_failure(amn) \
((amn)->amn_retrycnt > (amn)->amn_txcnt / 3)
#define is_enough(amn) \
((amn)->amn_txcnt > 10)
static void amrr_setinterval(const struct ieee80211vap *, int);
static void amrr_init(struct ieee80211vap *);
static void amrr_deinit(struct ieee80211vap *);
static void amrr_node_init(struct ieee80211_node *);
static void amrr_node_deinit(struct ieee80211_node *);
static int amrr_update(struct ieee80211_amrr *,
struct ieee80211_amrr_node *, struct ieee80211_node *);
static int amrr_rate(struct ieee80211_node *, void *, uint32_t);
static void amrr_tx_complete(const struct ieee80211vap *,
const struct ieee80211_node *, int,
void *, void *);
static void amrr_tx_update(const struct ieee80211vap *vap,
const struct ieee80211_node *, void *, void *, void *);
static void amrr_sysctlattach(struct ieee80211vap *,
struct sysctl_ctx_list *, struct sysctl_oid *);
/* number of references from net80211 layer */
static int nrefs = 0;
static const struct ieee80211_ratectl amrr = {
.ir_name = "amrr",
.ir_attach = NULL,
.ir_detach = NULL,
.ir_init = amrr_init,
.ir_deinit = amrr_deinit,
.ir_node_init = amrr_node_init,
.ir_node_deinit = amrr_node_deinit,
.ir_rate = amrr_rate,
.ir_tx_complete = amrr_tx_complete,
.ir_tx_update = amrr_tx_update,
.ir_setinterval = amrr_setinterval,
};
IEEE80211_RATECTL_MODULE(amrr, 1);
IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr);
static void
amrr_setinterval(const struct ieee80211vap *vap, int msecs)
{
struct ieee80211_amrr *amrr = vap->iv_rs;
int t;
if (msecs < 100)
msecs = 100;
t = msecs_to_ticks(msecs);
amrr->amrr_interval = (t < 1) ? 1 : t;
}
static void
amrr_init(struct ieee80211vap *vap)
{
struct ieee80211_amrr *amrr;
KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__));
amrr = vap->iv_rs = malloc(sizeof(struct ieee80211_amrr),
M_80211_RATECTL, M_NOWAIT|M_ZERO);
if (amrr == NULL) {
if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n");
return;
}
amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD;
amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD;
amrr_setinterval(vap, 500 /* ms */);
amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid);
}
static void
amrr_deinit(struct ieee80211vap *vap)
{
free(vap->iv_rs, M_80211_RATECTL);
}
/*
* Return whether 11n rates are possible.
*
* Some 11n devices may return HT information but no HT rates.
* Thus, we shouldn't treat them as an 11n node.
*/
static int
amrr_node_is_11n(struct ieee80211_node *ni)
{
if (ni->ni_chan == NULL)
return (0);
if (ni->ni_chan == IEEE80211_CHAN_ANYC)
return (0);
if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0)
return (0);
return (IEEE80211_IS_CHAN_HT(ni->ni_chan));
}
static void
amrr_node_init(struct ieee80211_node *ni)
{
const struct ieee80211_rateset *rs = NULL;
struct ieee80211vap *vap = ni->ni_vap;
struct ieee80211_amrr *amrr = vap->iv_rs;
struct ieee80211_amrr_node *amn;
uint8_t rate;
if (ni->ni_rctls == NULL) {
ni->ni_rctls = amn = malloc(sizeof(struct ieee80211_amrr_node),
M_80211_RATECTL, M_NOWAIT|M_ZERO);
if (amn == NULL) {
if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl "
"structure\n");
return;
}
} else
amn = ni->ni_rctls;
amn->amn_amrr = amrr;
amn->amn_success = 0;
amn->amn_recovery = 0;
amn->amn_txcnt = amn->amn_retrycnt = 0;
amn->amn_success_threshold = amrr->amrr_min_success_threshold;
/* 11n or not? Pick the right rateset */
if (amrr_node_is_11n(ni)) {
/* XXX ew */
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"%s: 11n node", __func__);
rs = (struct ieee80211_rateset *) &ni->ni_htrates;
} else {
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"%s: non-11n node", __func__);
rs = &ni->ni_rates;
}
/* Initial rate - lowest */
rate = rs->rs_rates[0];
/* XXX clear the basic rate flag if it's not 11n */
if (! amrr_node_is_11n(ni))
rate &= IEEE80211_RATE_VAL;
/* pick initial rate from the rateset - HT or otherwise */
/* Pick something low that's likely to succeed */
for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0;
amn->amn_rix--) {
/* legacy - anything < 36mbit, stop searching */
/* 11n - stop at MCS4 */
if (amrr_node_is_11n(ni)) {
if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4)
break;
} else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72)
break;
}
rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL;
/* if the rate is an 11n rate, ensure the MCS bit is set */
if (amrr_node_is_11n(ni))
rate |= IEEE80211_RATE_MCS;
/* Assign initial rate from the rateset */
ni->ni_txrate = rate;
amn->amn_ticks = ticks;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR: nrates=%d, initial rate %d",
rs->rs_nrates,
rate);
}
static void
amrr_node_deinit(struct ieee80211_node *ni)
{
free(ni->ni_rctls, M_80211_RATECTL);
}
static int
amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn,
struct ieee80211_node *ni)
{
int rix = amn->amn_rix;
const struct ieee80211_rateset *rs = NULL;
KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt));
/* 11n or not? Pick the right rateset */
if (amrr_node_is_11n(ni)) {
/* XXX ew */
rs = (struct ieee80211_rateset *) &ni->ni_htrates;
} else {
rs = &ni->ni_rates;
}
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR: current rate %d, txcnt=%d, retrycnt=%d",
rs->rs_rates[rix] & IEEE80211_RATE_VAL,
amn->amn_txcnt,
amn->amn_retrycnt);
/*
* XXX This is totally bogus for 11n, as although high MCS
* rates for each stream may be failing, the next stream
* should be checked.
*
* Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to
* MCS23, we should skip 6/7 and try 8 onwards.
*/
if (is_success(amn)) {
amn->amn_success++;
if (amn->amn_success >= amn->amn_success_threshold &&
rix + 1 < rs->rs_nrates) {
amn->amn_recovery = 1;
amn->amn_success = 0;
rix++;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR increasing rate %d (txcnt=%d retrycnt=%d)",
rs->rs_rates[rix] & IEEE80211_RATE_VAL,
amn->amn_txcnt, amn->amn_retrycnt);
} else {
amn->amn_recovery = 0;
}
} else if (is_failure(amn)) {
amn->amn_success = 0;
if (rix > 0) {
if (amn->amn_recovery) {
amn->amn_success_threshold *= 2;
if (amn->amn_success_threshold >
amrr->amrr_max_success_threshold)
amn->amn_success_threshold =
amrr->amrr_max_success_threshold;
} else {
amn->amn_success_threshold =
amrr->amrr_min_success_threshold;
}
rix--;
IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni,
"AMRR decreasing rate %d (txcnt=%d retrycnt=%d)",
rs->rs_rates[rix] & IEEE80211_RATE_VAL,
amn->amn_txcnt, amn->amn_retrycnt);
}
amn->amn_recovery = 0;
}
/* reset counters */
amn->amn_txcnt = 0;
amn->amn_retrycnt = 0;
return rix;
}
/*
* Return the rate index to use in sending a data frame.
* Update our internal state if it's been long enough.
* If the rate changes we also update ni_txrate to match.
*/
static int
amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused)
{
struct ieee80211_amrr_node *amn = ni->ni_rctls;
struct ieee80211_amrr *amrr = amn->amn_amrr;
const struct ieee80211_rateset *rs = NULL;
int rix;
/* 11n or not? Pick the right rateset */
if (amrr_node_is_11n(ni)) {
/* XXX ew */
rs = (struct ieee80211_rateset *) &ni->ni_htrates;
} else {
rs = &ni->ni_rates;
}
if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) {
rix = amrr_update(amrr, amn, ni);
if (rix != amn->amn_rix) {
/* update public rate */
ni->ni_txrate = rs->rs_rates[rix];
/* XXX strip basic rate flag from txrate, if non-11n */
if (amrr_node_is_11n(ni))
ni->ni_txrate |= IEEE80211_RATE_MCS;
else
ni->ni_txrate &= IEEE80211_RATE_VAL;
amn->amn_rix = rix;
}
amn->amn_ticks = ticks;
} else
rix = amn->amn_rix;
return rix;
}
/*
* Update statistics with tx complete status. Ok is non-zero
* if the packet is known to be ACK'd. Retries has the number
* retransmissions (i.e. xmit attempts - 1).
*/
static void
amrr_tx_complete(const struct ieee80211vap *vap,
const struct ieee80211_node *ni, int ok,
void *arg1, void *arg2 __unused)
{
struct ieee80211_amrr_node *amn = ni->ni_rctls;
int retries = *(int *)arg1;
amn->amn_txcnt++;
if (ok)
amn->amn_success++;
amn->amn_retrycnt += retries;
}
/*
* Set tx count/retry statistics explicitly. Intended for
* drivers that poll the device for statistics maintained
* in the device.
*/
static void
amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni,
void *arg1, void *arg2, void *arg3)
{
struct ieee80211_amrr_node *amn = ni->ni_rctls;
int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3;
amn->amn_txcnt = txcnt;
amn->amn_success = success;
amn->amn_retrycnt = retrycnt;
}
static int
amrr_sysctl_interval(SYSCTL_HANDLER_ARGS)
{
struct ieee80211vap *vap = arg1;
struct ieee80211_amrr *amrr = vap->iv_rs;
int msecs = ticks_to_msecs(amrr->amrr_interval);
int error;
error = sysctl_handle_int(oidp, &msecs, 0, req);
if (error || !req->newptr)
return error;
amrr_setinterval(vap, msecs);
return 0;
}
static void
amrr_sysctlattach(struct ieee80211vap *vap,
struct sysctl_ctx_list *ctx, struct sysctl_oid *tree)
{
struct ieee80211_amrr *amrr = vap->iv_rs;
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap,
0, amrr_sysctl_interval, "I", "amrr operation interval (ms)");
/* XXX bounds check values */
SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_max_sucess_threshold", CTLFLAG_RW,
&amrr->amrr_max_success_threshold, 0, "");
SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"amrr_min_sucess_threshold", CTLFLAG_RW,
&amrr->amrr_min_success_threshold, 0, "");
}