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 [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 7D30A3B29E for ; Sat, 19 Oct 2019 07:37:24 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571485044; 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=MVaudQUuQCI+ljMWLLAsex2zEz8cPUhBc2aoUxPRkR8=; b=h6VrtyZJohu1B6WWpIsP8cVK2D38xpHkZtGRduEppVTIROJ69SucJ+1KPsPfqIk4pumymy L+nte8u6s/wGSuBPLfJnu0UahwBegz6Ak97EdhtWldc+SsuklO2zdOE+oFMO3j5iiFmqDY bnB/jkixxNXbY/+sF74ocBb8oI3VxIM= Received: from mail-lj1-f199.google.com (mail-lj1-f199.google.com [209.85.208.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-48-uBnQQAxXOYG9HEXDIjqGXw-1; Sat, 19 Oct 2019 07:37:22 -0400 Received: by mail-lj1-f199.google.com with SMTP id e3so1618910ljj.16 for ; Sat, 19 Oct 2019 04:37:22 -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=KwtZFfw3+zEIBpCSK3JjIjdY2khNQMsybmZnMAvVGWM=; b=dfQFgrix0Rkchl9TRC3NKGdYNpsm+Xc8WbRSqM0BPthtq6TbK76wm2IelmPoaxTq2H GhrWoobUOmqroc6mpo9sRghX99LBUPBFvpIy5XyGwJBPu4zyYbrm5NrAtQO0T20N2SiM yfWvQF4/WAaFA5kmlovrxRs4RJZPCtOPW8VdQXjkrdu6wyR28wWEaCilusx/bgMqquxS kGHV3M5theLXgzVAMaCrG1QyITT/96n0xJaA95jsO94qqvsXT97ed2W2rQo4a39jzguT DoRsn30BO+wWFlNofMlzrx8GXciSk0CaaAnte+aslNCkN+Jao0o+RgTjns7BZ50FU1/6 w66A== X-Gm-Message-State: APjAAAVqyuQB4857agYRNIxLeZr9tZSvcFvXuoDdN3dFwRpVHz4dc5Bo 0oaKRRjyTkqzMoEnDKtq2VNA9tKczNmXqkE1o3riNlTjz/VgG/UBrB6Rwh8q1f3EX8Mr4PlNrk+ hrK8f++hkk1/nJI1ophdYykKyEU96I9IcO8A= X-Received: by 2002:a19:9146:: with SMTP id y6mr645546lfj.11.1571485040858; Sat, 19 Oct 2019 04:37:20 -0700 (PDT) X-Google-Smtp-Source: APXvYqy6A2s0kb12rWbr+kZlB9sAojMXKwZLl1GcZkznDPvWiSSK5d9yqvGSQlvsPztMK75+Z9uVsw== X-Received: by 2002:a19:9146:: with SMTP id y6mr645532lfj.11.1571485040619; Sat, 19 Oct 2019 04:37:20 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk (borgediget.toke.dk. [85.204.121.218]) by smtp.gmail.com with ESMTPSA id h3sm5459652ljf.12.2019.10.19.04.37.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Oct 2019 04:37:19 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id BD12A1804C8; Sat, 19 Oct 2019 13:37:18 +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: Sat, 19 Oct 2019 13:37:18 +0200 Message-ID: <157148503865.2989444.7118792679603045723.stgit@toke.dk> In-Reply-To: <157148503415.2989444.7391437309981941226.stgit@toke.dk> References: <157148503415.2989444.7391437309981941226.stgit@toke.dk> User-Agent: StGit/0.20 MIME-Version: 1.0 X-MC-Unique: uBnQQAxXOYG9HEXDIjqGXw-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Subject: [Make-wifi-fast] [PATCH v4 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: Sat, 19 Oct 2019 11:37:24 -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 | 21 +++++++++++++++++++++ 2 files changed, 59 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..b8ff56d1d661 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -3542,6 +3542,9 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211= _hw *hw, =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 +3655,24 @@ 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=09u32 airtime; + +=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 the maximum to 2**12-1 +=09=09=09 */ +=09=09=09airtime =3D min_t(u32, airtime, 4095) & ~3U; +=09=09=09info->tx_time_est =3D airtime >> 2; +=09=09=09ieee80211_sta_update_pending_airtime(local, tx.sta, +=09=09=09=09=09=09=09 txq->ac, airtime, +=09=09=09=09=09=09=09 false); +=09=09} +=09} + =09return skb; =20 out: