[Make-wifi-fast] [RFC/RFT 4/5] ath9k: Add a per-station airtime deficit scheduler
Toke Høiland-Jørgensen
toke at toke.dk
Fri Jun 3 12:51:43 EDT 2016
This modifies the logic in ath_txq_schedule to account airtime consumed
by each station and uses a deficit-based scheduler derived from FQ-CoDel
to try to enforce airtime fairness. The deficit is decreased on TX
completion and the scheduler simply makes scheduling decisions based on
this.
Signed-off-by: Toke Høiland-Jørgensen <toke at toke.dk>
---
drivers/net/wireless/ath/ath9k/ath9k.h | 8 ++-
drivers/net/wireless/ath/ath9k/channel.c | 12 ++--
drivers/net/wireless/ath/ath9k/debug.h | 8 +++
drivers/net/wireless/ath/ath9k/debug_sta.c | 12 ++++
drivers/net/wireless/ath/ath9k/main.c | 6 +-
drivers/net/wireless/ath/ath9k/xmit.c | 99 ++++++++++++++++++++++++------
6 files changed, 117 insertions(+), 28 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 3fbb0ad..7c0fc8b 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -261,6 +261,7 @@ struct ath_node {
bool sleeping;
bool no_ps_filter;
+ s64 airtime_deficit;
#ifdef CONFIG_ATH9K_STATION_STATISTICS
struct ath_rx_rate_stats rx_rate_stats;
@@ -332,10 +333,15 @@ struct ath_rx {
/* Channel Context */
/*******************/
+struct ath_acq {
+ struct list_head acq_new;
+ struct list_head acq_old;
+};
+
struct ath_chanctx {
struct cfg80211_chan_def chandef;
struct list_head vifs;
- struct list_head acq[IEEE80211_NUM_ACS];
+ struct ath_acq acq[IEEE80211_NUM_ACS];
int hw_queue_base;
/* do not dereference, use for comparison only */
diff --git a/drivers/net/wireless/ath/ath9k/channel.c b/drivers/net/wireless/ath/ath9k/channel.c
index e56bafc..2594029 100644
--- a/drivers/net/wireless/ath/ath9k/channel.c
+++ b/drivers/net/wireless/ath/ath9k/channel.c
@@ -118,8 +118,10 @@ void ath_chanctx_init(struct ath_softc *sc)
INIT_LIST_HEAD(&ctx->vifs);
ctx->txpower = ATH_TXPOWER_MAX;
ctx->flush_timeout = HZ / 5; /* 200ms */
- for (j = 0; j < ARRAY_SIZE(ctx->acq); j++)
- INIT_LIST_HEAD(&ctx->acq[j]);
+ for (j = 0; j < ARRAY_SIZE(ctx->acq); j++) {
+ INIT_LIST_HEAD(&ctx->acq[j].acq_new);
+ INIT_LIST_HEAD(&ctx->acq[j].acq_old);
+ }
}
}
@@ -1344,8 +1346,10 @@ void ath9k_offchannel_init(struct ath_softc *sc)
ctx->txpower = ATH_TXPOWER_MAX;
cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
- for (i = 0; i < ARRAY_SIZE(ctx->acq); i++)
- INIT_LIST_HEAD(&ctx->acq[i]);
+ for (i = 0; i < ARRAY_SIZE(ctx->acq); i++) {
+ INIT_LIST_HEAD(&ctx->acq[i].acq_new);
+ INIT_LIST_HEAD(&ctx->acq[i].acq_old);
+ }
sc->offchannel.chan.offchannel = true;
}
diff --git a/drivers/net/wireless/ath/ath9k/debug.h b/drivers/net/wireless/ath/ath9k/debug.h
index 4f78495..bf1a540 100644
--- a/drivers/net/wireless/ath/ath9k/debug.h
+++ b/drivers/net/wireless/ath/ath9k/debug.h
@@ -327,6 +327,9 @@ void ath_debug_tx_airtime(struct ath_softc *sc,
void ath_debug_rx_airtime(struct ath_softc *sc,
struct ath_rx_status *rs,
struct sk_buff *skb);
+void ath_debug_airtime(struct ath_softc *sc,
+ struct ath_node *an,
+ u32 rx, u32 tx);
#else
static inline void ath_debug_rate_stats(struct ath_softc *sc,
struct ath_rx_status *rs,
@@ -343,6 +346,11 @@ static inline void ath_debug_rx_airtime(struct ath_softc *sc,
struct sk_buff *skb)
{
}
+static void ath_debug_airtime(struct ath_softc *sc,
+ struct ath_node *an,
+ u32 rx, u32 tx)
+{
+}
#endif /* CONFIG_ATH9K_STATION_STATISTICS */
#endif /* DEBUG_H */
diff --git a/drivers/net/wireless/ath/ath9k/debug_sta.c b/drivers/net/wireless/ath/ath9k/debug_sta.c
index 56aba3a..2313f9e 100644
--- a/drivers/net/wireless/ath/ath9k/debug_sta.c
+++ b/drivers/net/wireless/ath/ath9k/debug_sta.c
@@ -245,6 +245,17 @@ static const struct file_operations fops_node_recv = {
.llseek = default_llseek,
};
+void ath_debug_airtime(struct ath_softc *sc,
+ struct ath_node *an,
+ u32 rx,
+ u32 tx)
+{
+ struct ath_airtime_stats *astats = &an->airtime_stats;
+
+ astats->rx_airtime += rx;
+ astats->tx_airtime += tx;
+}
+
void ath_debug_tx_airtime(struct ath_softc *sc,
struct ath_buf *bf,
struct ath_tx_status *ts)
@@ -353,6 +364,7 @@ static ssize_t read_airtime(struct file *file, char __user *user_buf,
len += scnprintf(buf + len, size - len, "RX: %u us\n", astats->rx_airtime);
len += scnprintf(buf + len, size - len, "TX: %u us\n", astats->tx_airtime);
+ len += scnprintf(buf + len, size - len, "Deficit: %lld us\n", an->airtime_deficit);
retval = simple_read_from_buffer(user_buf, count, ppos, buf, len);
kfree(buf);
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 6ab56e5..e13068b 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -70,10 +70,10 @@ static bool ath9k_has_pending_frames(struct ath_softc *sc, struct ath_txq *txq,
goto out;
if (txq->mac80211_qnum >= 0) {
- struct list_head *list;
+ struct ath_acq *acq;
- list = &sc->cur_chan->acq[txq->mac80211_qnum];
- if (!list_empty(list))
+ acq = &sc->cur_chan->acq[txq->mac80211_qnum];
+ if (!list_empty(&acq->acq_new) || !list_empty(&acq->acq_old))
pending = true;
}
out:
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 07d32e7..6ce58d9 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -108,16 +108,17 @@ void ath_txq_unlock_complete(struct ath_softc *sc, struct ath_txq *txq)
static void ath_tx_queue_tid(struct ath_softc *sc, struct ath_txq *txq,
struct ath_atx_tid *tid)
{
- struct list_head *list;
struct ath_vif *avp = (struct ath_vif *) tid->an->vif->drv_priv;
struct ath_chanctx *ctx = avp->chanctx;
+ struct ath_acq *acq;
if (!ctx)
return;
- list = &ctx->acq[TID_TO_WME_AC(tid->tidno)];
+
+ acq = &ctx->acq[TID_TO_WME_AC(tid->tidno)];
if (list_empty(&tid->list))
- list_add_tail(&tid->list, list);
+ list_add_tail(&tid->list, &acq->acq_new);
}
void ath9k_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *swq)
@@ -722,6 +723,47 @@ static bool bf_is_ampdu_not_probing(struct ath_buf *bf)
return bf_isampdu(bf) && !(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
}
+static void ath_tx_count_airtime(struct ath_softc *sc,
+ struct ath_buf *bf,
+ struct ath_tx_status *ts)
+{
+ struct ath_node *an;
+ struct sk_buff *skb;
+ struct ieee80211_hdr *hdr;
+ struct ieee80211_hw *hw = sc->hw;
+ struct ieee80211_tx_rate rates[4];
+ struct ieee80211_sta *sta;
+ int i;
+ u32 airtime = 0;
+
+ skb = bf->bf_mpdu;
+ if(!skb)
+ return;
+
+ hdr = (struct ieee80211_hdr *)skb->data;
+ memcpy(rates, bf->rates, sizeof(rates));
+
+ rcu_read_lock();
+
+ sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr1, hdr->addr2);
+ if(!sta)
+ goto exit;
+
+
+ an = (struct ath_node *) sta->drv_priv;
+
+ airtime += ts->duration * (ts->ts_longretry + 1);
+
+ for(i=0; i < ts->ts_rateindex; i++)
+ airtime += ath9k_hw_get_duration(sc->sc_ah, bf->bf_desc, i) * rates[i].count;
+
+ an->airtime_deficit -= airtime;
+ ath_debug_airtime(sc, an, 0, airtime);
+
+exit:
+ rcu_read_unlock();
+}
+
static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
struct ath_tx_status *ts, struct ath_buf *bf,
struct list_head *bf_head)
@@ -739,7 +781,7 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
ts->duration = ath9k_hw_get_duration(sc->sc_ah, bf->bf_desc,
ts->ts_rateindex);
- ath_debug_tx_airtime(sc, bf, ts);
+ ath_tx_count_airtime(sc, bf, ts);
if (!bf_isampdu(bf)) {
if (!flush) {
@@ -1989,6 +2031,7 @@ void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq)
struct ath_common *common = ath9k_hw_common(sc->sc_ah);
struct ath_atx_tid *tid, *last_tid;
struct list_head *tid_list;
+ struct ath_acq *acq;
bool sent = false;
if (txq->mac80211_qnum < 0)
@@ -1998,37 +2041,51 @@ void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq)
return;
spin_lock_bh(&sc->chan_lock);
- tid_list = &sc->cur_chan->acq[txq->mac80211_qnum];
-
- if (list_empty(tid_list)) {
- spin_unlock_bh(&sc->chan_lock);
- return;
- }
+ acq = &sc->cur_chan->acq[txq->mac80211_qnum];
rcu_read_lock();
+ tid_list = &acq->acq_new;
+ if (list_empty(tid_list)) {
+ tid_list = &acq->acq_old;
+ if (list_empty(tid_list))
+ goto out;
+ }
last_tid = list_entry(tid_list->prev, struct ath_atx_tid, list);
- while (!list_empty(tid_list)) {
+ for (;;) {
bool stop = false;
if (sc->cur_chan->stopped)
break;
- tid = list_first_entry(tid_list, struct ath_atx_tid, list);
- list_del_init(&tid->list);
+ tid = list_first_entry_or_null(tid_list, struct ath_atx_tid, list);
+ if (!tid)
+ break;
+
+ if (tid->an->airtime_deficit <= 0) {
+ tid->an->airtime_deficit += 300;
+ list_move_tail(&tid->list, &acq->acq_old);
+ continue;
+ }
+
if (ath_tx_sched_aggr(sc, txq, tid, &stop))
sent = true;
+ /* Give this tid a chance to try again when we have hw buffer space */
+ if (stop)
+ break;
+
/*
- * add tid to round-robin queue if more frames
- * are pending for the tid
+ * If we still have packets or we're in the new list, we need to
+ * pass through old list. The latter case is to prevent
+ * starvation.
*/
- if (ath_tid_has_buffered(tid))
- ath_tx_queue_tid(sc, txq, tid);
+ if (ath_tid_has_buffered(tid) || ((tid_list == &acq->acq_new) && !list_empty(&acq->acq_old)))
+ list_move_tail(&tid->list, &acq->acq_old);
+ else
+ list_del_init(&tid->list);
- if (stop)
- break;
if (tid == last_tid) {
if (!sent)
@@ -2039,7 +2096,7 @@ void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq)
struct ath_atx_tid, list);
}
}
-
+out:
rcu_read_unlock();
spin_unlock_bh(&sc->chan_lock);
}
@@ -2934,6 +2991,8 @@ void ath_tx_node_init(struct ath_softc *sc, struct ath_node *an)
struct ath_atx_tid *tid;
int tidno, acno;
+ an->airtime_deficit = 300;
+
for (tidno = 0;
tidno < IEEE80211_NUM_TIDS;
tidno++) {
--
2.7.4
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