Hi Toke,
This patch looks good to me. Great job on getting the airtime fairness
scheduling framework done!
On Tue, Jan 22, 2019 at 6:21 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
>
> From: Kan Yan <kyan@xxxxxxxxxx>
>
> Transmit airtime will be estimated from last tx rate used.
> Firmware report tx rate by peer stats. Airtime is computed
> on tx path and the same will be reported to mac80211 upon
> tx completion.
>
> This change is based on Kan's orginal commit in Chromium tree
> ("CHROMIUM: ath10k: Implementing airtime fairness based TX scheduler")
> ref: https://chromium-review.googlesource.com/588190
>
> Tested on QCA4019 with firmware version 10.4-3.2.1.1-00015
> Tested on QCA9984 with firmware version 10.4-3.9.0.1-00005
>
> Signed-off-by: Kan Yan <kyan@xxxxxxxxxx>
> [rmanohar@xxxxxxxxxxxxxx: ported only the airtime computation]
> Signed-off-by: Rajkumar Manoharan <rmanohar@xxxxxxxxxxxxxx>
> [toke@xxxxxxxxxx: Rebase to mac80211-next, add test note]
> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> ---
>
> Rajkumar / Kan: Please check that I didn't mess anything up while
> rebasing this onto the current mac80211-next branch!
>
> drivers/net/wireless/ath/ath10k/core.h | 2 +
> drivers/net/wireless/ath/ath10k/htt_rx.c | 1 +
> drivers/net/wireless/ath/ath10k/mac.c | 57 ++++++++++++++++++++++--
> drivers/net/wireless/ath/ath10k/txrx.c | 4 ++
> 4 files changed, 61 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
> index 28cecf7375f8..4528a6e47b8d 100644
> --- a/drivers/net/wireless/ath/ath10k/core.h
> +++ b/drivers/net/wireless/ath/ath10k/core.h
> @@ -126,6 +126,7 @@ struct ath10k_skb_cb {
> u8 flags;
> u8 eid;
> u16 msdu_id;
> + u16 airtime_est;
> struct ieee80211_vif *vif;
> struct ieee80211_txq *txq;
> } __packed;
> @@ -498,6 +499,7 @@ struct ath10k_sta {
> u16 peer_id;
> struct rate_info txrate;
> struct ieee80211_tx_info tx_info;
> + u32 last_tx_bitrate;
>
> struct work_struct update_wk;
> u64 rx_duration;
> diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
> index dc9895f2eb9d..6a93b57900ae 100644
> --- a/drivers/net/wireless/ath/ath10k/htt_rx.c
> +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
> @@ -3078,6 +3078,7 @@ ath10k_update_per_peer_tx_stats(struct ath10k *ar,
>
> arsta->txrate.nss = txrate.nss;
> arsta->txrate.bw = ath10k_bw_to_mac80211_bw(txrate.bw);
> + arsta->last_tx_bitrate = cfg80211_calculate_bitrate(&arsta->txrate);
> if (sgi)
> arsta->txrate.flags |= RATE_INFO_FLAGS_SHORT_GI;
>
> diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
> index cf7fdf72e990..b13dcb4533cb 100644
> --- a/drivers/net/wireless/ath/ath10k/mac.c
> +++ b/drivers/net/wireless/ath/ath10k/mac.c
> @@ -3544,7 +3544,7 @@ static void ath10k_tx_h_add_p2p_noa_ie(struct ath10k *ar,
> static void ath10k_mac_tx_h_fill_cb(struct ath10k *ar,
> struct ieee80211_vif *vif,
> struct ieee80211_txq *txq,
> - struct sk_buff *skb)
> + struct sk_buff *skb, u16 airtime)
> {
> struct ieee80211_hdr *hdr = (void *)skb->data;
> struct ath10k_skb_cb *cb = ATH10K_SKB_CB(skb);
> @@ -3561,6 +3561,7 @@ static void ath10k_mac_tx_h_fill_cb(struct ath10k *ar,
>
> cb->vif = vif;
> cb->txq = txq;
> + cb->airtime_est = airtime;
> }
>
> bool ath10k_mac_tx_frm_has_freq(struct ath10k *ar)
> @@ -3948,6 +3949,49 @@ static bool ath10k_mac_tx_can_push(struct ieee80211_hw *hw,
> return false;
> }
>
> +/* Return estimated airtime in microsecond, which is calculated using last
> + * reported TX rate. This is just a rough estimation because host driver has no
> + * knowledge of the actual transmit rate, retries or aggregation. If actual
> + * airtime can be reported by firmware, then delta between estimated and actual
> + * airtime can be adjusted from deficit.
> + */
> +#define IEEE80211_ATF_OVERHEAD 100 /* IFS + some slot time */
> +#define IEEE80211_ATF_OVERHEAD_IFS 16 /* IFS only */
> +static u16 ath10k_mac_update_airtime(struct ath10k *ar,
> + struct ieee80211_txq *txq,
> + struct sk_buff *skb)
> +{
> + struct ath10k_sta *arsta;
> + u32 pktlen;
> + u16 airtime = 0;
> +
> + if (!txq || !txq->sta)
> + return airtime;
> +
> + spin_lock_bh(&ar->data_lock);
> + arsta = (struct ath10k_sta *)txq->sta->drv_priv;
> +
> + pktlen = skb->len + 38; /* Assume MAC header 30, SNAP 8 for most case */
> + if (arsta->last_tx_bitrate) {
> + /* airtime in us, last_tx_bitrate in 100kbps */
> + airtime = (pktlen * 8 * (1000 / 100))
> + / arsta->last_tx_bitrate;
> + /* overhead for media access time and IFS */
> + airtime += IEEE80211_ATF_OVERHEAD_IFS;
> + } else {
> + /* This is mostly for throttle excessive BC/MC frames, and the
> + * airtime/rate doesn't need be exact. Airtime of BC/MC frames
> + * in 2G get some discount, which helps prevent very low rate
> + * frames from being blocked for too long.
> + */
> + airtime = (pktlen * 8 * (1000 / 100)) / 60; /* 6M */
> + airtime += IEEE80211_ATF_OVERHEAD;
> + }
> + spin_unlock_bh(&ar->data_lock);
> +
> + return airtime;
> +}
> +
> int ath10k_mac_tx_push_txq(struct ieee80211_hw *hw,
> struct ieee80211_txq *txq)
> {
> @@ -3963,6 +4007,7 @@ int ath10k_mac_tx_push_txq(struct ieee80211_hw *hw,
> size_t skb_len;
> bool is_mgmt, is_presp;
> int ret;
> + u16 airtime;
>
> spin_lock_bh(&ar->htt.tx_lock);
> ret = ath10k_htt_tx_inc_pending(htt);
> @@ -3980,7 +4025,8 @@ int ath10k_mac_tx_push_txq(struct ieee80211_hw *hw,
> return -ENOENT;
> }
>
> - ath10k_mac_tx_h_fill_cb(ar, vif, txq, skb);
> + airtime = ath10k_mac_update_airtime(ar, txq, skb);
> + ath10k_mac_tx_h_fill_cb(ar, vif, txq, skb, airtime);
>
> skb_len = skb->len;
> txmode = ath10k_mac_tx_h_get_txmode(ar, vif, sta, skb);
> @@ -4247,8 +4293,10 @@ static void ath10k_mac_op_tx(struct ieee80211_hw *hw,
> bool is_mgmt;
> bool is_presp;
> int ret;
> + u16 airtime;
>
> - ath10k_mac_tx_h_fill_cb(ar, vif, txq, skb);
> + airtime = ath10k_mac_update_airtime(ar, txq, skb);
> + ath10k_mac_tx_h_fill_cb(ar, vif, txq, skb, airtime);
>
> txmode = ath10k_mac_tx_h_get_txmode(ar, vif, sta, skb);
> txpath = ath10k_mac_tx_h_get_txpath(ar, skb, txmode);
> @@ -8603,6 +8651,9 @@ int ath10k_mac_register(struct ath10k *ar)
> wiphy_ext_feature_set(ar->hw->wiphy,
> NL80211_EXT_FEATURE_ACK_SIGNAL_SUPPORT);
>
> + if (ath10k_peer_stats_enabled(ar))
> + wiphy_ext_feature_set(ar->hw->wiphy,
> + NL80211_EXT_FEATURE_AIRTIME_FAIRNESS);
> /*
> * on LL hardware queues are managed entirely by the FW
> * so we only advertise to mac we can do the queues thing
> diff --git a/drivers/net/wireless/ath/ath10k/txrx.c b/drivers/net/wireless/ath/ath10k/txrx.c
> index 23606b6972d0..8e7c416cd330 100644
> --- a/drivers/net/wireless/ath/ath10k/txrx.c
> +++ b/drivers/net/wireless/ath/ath10k/txrx.c
> @@ -95,6 +95,10 @@ int ath10k_txrx_tx_unref(struct ath10k_htt *htt,
> wake_up(&htt->empty_tx_wq);
> spin_unlock_bh(&htt->tx_lock);
>
> + if (txq && txq->sta)
> + ieee80211_sta_register_airtime(txq->sta, txq->tid,
> + skb_cb->airtime_est, 0);
> +
> if (ar->dev_type != ATH10K_DEV_TYPE_HL)
> dma_unmap_single(dev, skb_cb->paddr, msdu->len, DMA_TO_DEVICE);
>
> --
> 2.20.1
>
