Return-path: Received: from mail2.tohojo.dk ([77.235.48.147]:37160 "EHLO mail2.tohojo.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752724AbcFCQwi convert rfc822-to-8bit (ORCPT ); Fri, 3 Jun 2016 12:52:38 -0400 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= To: linux-wireless@vger.kernel.org, make-wifi-fast@lists.bufferbloat.net, ath9k-devel@lists.ath9k.org Cc: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Subject: [RFC/RFT 4/5] ath9k: Add a per-station airtime deficit scheduler Date: Fri, 3 Jun 2016 18:51:43 +0200 Message-Id: <20160603165144.17356-5-toke@toke.dk> (sfid-20160603_185242_098839_29438C2A) In-Reply-To: <20160603165144.17356-1-toke@toke.dk> References: <20160603165144.17356-1-toke@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 --- 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