From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 5B8AD3CB48 for ; Fri, 18 Oct 2019 10:40:32 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571409632; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lqBYAyfvGqVBfvQQyb/0J8hd/48vyEbBcTT/es8g2a8=; b=MoIIOC8+qrdS+TlqhRI9z88mCtZXyxGX8/pQfE6crucx6v/H7flf01+fF2IXb4sdO2uT80 8TiuT2x1E31l2jkbDSBPAg8xFWW2kq8uPj7EB4sBVSTKJ+bdYw8OmtbZFBndY4lgmnCqdb Ju3wWNuCw0zdTJJetq1bO/YKwxNa1cU= Received: from mail-lj1-f198.google.com (mail-lj1-f198.google.com [209.85.208.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-317-ahPDpI9TNuSJ7_8w08zRkw-1; Fri, 18 Oct 2019 10:40:28 -0400 Received: by mail-lj1-f198.google.com with SMTP id m22so1126051ljj.6 for ; Fri, 18 Oct 2019 07:40:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=B/zTxrtPVbDPMk1jNIRjvApKrsIv0Uj3+z7s63i2jdw=; b=TioYKpqdyH+82hKrhZulmm+mYTJbfhyACuLq34jXRFcLAr7D+Drkim1QTfRxMRyIcd T8Hh+y/YnwyLKrNyDafoGztjf4vlBtIrKPJH7QMuo9FeX1TY4OnZAfQrXKIAic3dJrfa Tgv6WtWgHZB52U+VQqBFlUbkjhdULXpxeRX9HqaI1Tnjtuv6Cp1GJaQ3XbxnAbt7qWaT N0QHrkG674oWYH0/MzE8ZMgTVHKQkI+Rhw/iCbx7VP4Vs+yWu9UN04tt67DfB4I/A/RB HxoPrG03z1JZm7v7cwDxll/t6AZF7/UBP1/+9dvfgFtW6ppIz763w7g9QkekOtr57X7c rXzg== X-Gm-Message-State: APjAAAVH0og22nsmRabQ7ee1baftNk9evQqgJQSYMd6So1Fcb/HxfYvY cOgaf2iXEUNaFxVMD8UrJ4C4taSrOf2CvM50rEisb9nfaCvQX5wdSugWhzsSmHV35/WxIjZ41Gy vgeAF/mJM4WhmPKU3xMRXzXVrKNKurZpDdFo= X-Received: by 2002:a2e:5dd5:: with SMTP id v82mr6545674lje.54.1571409627127; Fri, 18 Oct 2019 07:40:27 -0700 (PDT) X-Google-Smtp-Source: APXvYqxolQE2snCfRFv7NPp6VkDcPkPnM67ptbRrwbO/RDkqMvooRv8yklzlnAGDuCtp1Rd02Oj9BA== X-Received: by 2002:a2e:5dd5:: with SMTP id v82mr6545664lje.54.1571409626863; Fri, 18 Oct 2019 07:40:26 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([2a00:7660:6da:443::2]) by smtp.gmail.com with ESMTPSA id d25sm2572501lfj.15.2019.10.18.07.40.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Oct 2019 07:40:26 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 6A8AC1804B6; Fri, 18 Oct 2019 16:40:25 +0200 (CEST) From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Johannes Berg Cc: linux-wireless@vger.kernel.org, make-wifi-fast@lists.bufferbloat.net, ath10k@lists.infradead.org, John Crispin , Lorenzo Bianconi , Felix Fietkau , Kan Yan , Rajkumar Manoharan , Kevin Hayes Date: Fri, 18 Oct 2019 16:40:25 +0200 Message-ID: <157140962534.2866668.1182822483250825739.stgit@toke.dk> In-Reply-To: <157140962094.2866668.3383184317264069493.stgit@toke.dk> References: <157140962094.2866668.3383184317264069493.stgit@toke.dk> User-Agent: StGit/0.20 MIME-Version: 1.0 X-MC-Unique: ahPDpI9TNuSJ7_8w08zRkw-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Subject: [Make-wifi-fast] [PATCH v3 4/4] mac80211: Use Airtime-based Queue Limits (AQL) on packet dequeue X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Oct 2019 14:40:32 -0000 From: Toke H=C3=B8iland-J=C3=B8rgensen The previous commit added the ability to throttle stations when they queue too much airtime in the hardware. This commit enables the functionality by calculating the expected airtime usage of each packet that is dequeued from the TXQs in mac80211, and accounting that as pending airtime. The estimated airtime for each skb is stored in the tx_info, so we can subtract the same amount from the running total when the skb is freed or recycled. The throttling mechanism relies on this accounting to be accurate (i.e., that we are not freeing skbs without subtracting any airtime they were accounted for), so we put the subtraction into ieee80211_report_used_skb(). As an optimisation, we also subtract the airtime on regular TX completion, zeroing out the value stored in the packet afterwards, to avoid having to do an expensive lookup of the station from the packet data on every packet. This patch does *not* include any mechanism to wake a throttled TXQ again, on the assumption that this will happen anyway as a side effect of whatever freed the skb (most commonly a TX completion). Signed-off-by: Toke H=C3=B8iland-J=C3=B8rgensen --- net/mac80211/status.c | 38 ++++++++++++++++++++++++++++++++++++++ net/mac80211/tx.c | 19 +++++++++++++++++++ 2 files changed, 57 insertions(+) diff --git a/net/mac80211/status.c b/net/mac80211/status.c index ab8ba5835ca0..905b4afd457d 100644 --- a/net/mac80211/status.c +++ b/net/mac80211/status.c @@ -676,6 +676,33 @@ static void ieee80211_report_used_skb(struct ieee80211= _local *local, =09if (dropped) =09=09acked =3D false; =20 +=09if (info->tx_time_est) { +=09=09struct ieee80211_sub_if_data *sdata; +=09=09struct sta_info *sta =3D NULL; +=09=09u8 *qc, ac; +=09=09int tid; + +=09=09rcu_read_lock(); + +=09=09sdata =3D ieee80211_sdata_from_skb(local, skb); +=09=09if (sdata) +=09=09=09sta =3D sta_info_get_bss(sdata, skb_mac_header(skb)); + +=09=09if (ieee80211_is_data_qos(hdr->frame_control)) { +=09=09=09qc =3D ieee80211_get_qos_ctl(hdr); +=09=09=09tid =3D qc[0] & 0xf; +=09=09=09ac =3D ieee80211_ac_from_tid(tid); +=09=09} else { +=09=09=09ac =3D IEEE80211_AC_BE; +=09=09} + +=09=09ieee80211_sta_update_pending_airtime(local, sta, ac, +=09=09=09=09=09=09 info->tx_time_est << 2, +=09=09=09=09=09=09 true); +=09=09rcu_read_unlock(); + +=09} + =09if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) { =09=09struct ieee80211_sub_if_data *sdata; =20 @@ -930,6 +957,17 @@ static void __ieee80211_tx_status(struct ieee80211_hw = *hw, =09=09=09tid =3D qc[0] & 0xf; =09=09} =20 +=09=09if (info->tx_time_est) { +=09=09=09/* Do this here to avoid the expensive lookup of the sta +=09=09=09 * in ieee80211_report_used_skb(). +=09=09=09 */ +=09=09=09ieee80211_sta_update_pending_airtime(local, sta, +=09=09=09=09=09=09=09 ieee80211_ac_from_tid(tid), +=09=09=09=09=09=09=09 info->tx_time_est << 2, +=09=09=09=09=09=09=09 true); +=09=09=09info->tx_time_est =3D 0; +=09=09} + =09=09if (!acked && ieee80211_is_back_req(fc)) { =09=09=09u16 control; =20 diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 12653d873b8c..bd8284f04361 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -3539,9 +3539,14 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee8021= 1_hw *hw, =09struct ieee80211_tx_data tx; =09ieee80211_tx_result r; =09struct ieee80211_vif *vif =3D txq->vif; +=09u8 ac =3D txq->ac; +=09u32 airtime; =20 =09WARN_ON_ONCE(softirq_count() =3D=3D 0); =20 +=09if (!ieee80211_txq_airtime_check(hw, txq)) +=09=09return NULL; + begin: =09spin_lock_bh(&fq->lock); =20 @@ -3652,6 +3657,20 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee8021= 1_hw *hw, =09} =20 =09IEEE80211_SKB_CB(skb)->control.vif =3D vif; + +=09if (local->airtime_flags & AIRTIME_USE_AQL) { +=09=09airtime =3D ieee80211_calc_expected_tx_airtime(hw, vif, txq->sta, +=09=09=09=09=09=09=09 skb->len); +=09=09if (airtime) { +=09=09=09/* We only have 10 bits in tx_time_est, so store airtime +=09=09=09 * in increments of 4 us and clamp that to 2**10. +=09=09=09 */ +=09=09=09info->tx_time_est =3D min_t(u32, airtime >> 2, 1 << 10); +=09=09=09ieee80211_sta_update_pending_airtime(local, tx.sta, ac, +=09=09=09=09=09=09=09 airtime, false); +=09=09} +=09} + =09return skb; =20 out: