From patchwork Fri Oct 18 14:40:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 11198605 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 69EFE913 for ; Fri, 18 Oct 2019 14:40:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 432AE222C5 for ; Fri, 18 Oct 2019 14:40:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="jFSOqBde" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2634141AbfJROkc (ORCPT ); Fri, 18 Oct 2019 10:40:32 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:26970 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2410018AbfJROkc (ORCPT ); Fri, 18 Oct 2019 10:40:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571409630; 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=jFSOqBdeeUyrapoZYGsbTVp11SJVvfBO8VNUYHi0z8AsGXOH6lnHRVag7veTte8IuRFhj2 sTTkySeSGH/174pwPIGqHmAjI9HNO01V5xEZzC906uQ05lbQaR8ZooZUxZPahCTRpnDjxc 05o3KNOMz790eJ21+KUQpHRKQrW1PCI= Received: from mail-lf1-f72.google.com (mail-lf1-f72.google.com [209.85.167.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-12-FShSDlISMPm3bVlutHFqSA-1; Fri, 18 Oct 2019 10:40:28 -0400 Received: by mail-lf1-f72.google.com with SMTP id c7so1327757lfh.9 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=cWddvK9qx15r/f/3sliMVEOkgOQsP3kD6xxaakHm0hasy6B8/wAfRA3OKCwsOiOI8Y 0mcX70btzMTZSaP2VHXZvQj8OontRbjO2LKxlI+pXb2i/fNphfm/E2XhEBIu6ktBxMVT zkh/L6K0SmqGrzNiL332Q7BOGNQSnEBS1GgmJJH6zs9U67WXBt6N5cjnrvldwwQxzpuo 6/IpOjHIubXMEZnf/1ukrrelI+IRzAy25LPlJMk4mVTuE92nBuu6ap6+bwC8CukRzgQV 1yJsEjascZt1nRM31p6WodH9rvm1NJf4X9FHx1+xc5Tyc5FYUE9h6Iah8m8XjTJnzsvf MkDA== X-Gm-Message-State: APjAAAXeYDCY8mzCNeAALkUovI0eBIM7GlHEuT1CuhUJUfcQPOX6HByg mj0pMqLRAEVZnS4nCdMFdGqY3MF6oZLCeYNQVR8VnFgecQSDQIWU3Q3GQcSuB3uJ/xUSMhAkS3e IdYyB+7hk+WlW2J9xnAWQUqgWg/Y= X-Received: by 2002:a2e:5dd5:: with SMTP id v82mr6545681lje.54.1571409627129; 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) Subject: [PATCH v3 4/4] mac80211: Use Airtime-based Queue Limits (AQL) on packet dequeue 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: FShSDlISMPm3bVlutHFqSA-1 X-Mimecast-Spam-Score: 0 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Toke Høiland-Jørgensen 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 Høiland-Jørgensen --- 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, if (dropped) acked = false; + if (info->tx_time_est) { + struct ieee80211_sub_if_data *sdata; + struct sta_info *sta = NULL; + u8 *qc, ac; + int tid; + + rcu_read_lock(); + + sdata = ieee80211_sdata_from_skb(local, skb); + if (sdata) + sta = sta_info_get_bss(sdata, skb_mac_header(skb)); + + if (ieee80211_is_data_qos(hdr->frame_control)) { + qc = ieee80211_get_qos_ctl(hdr); + tid = qc[0] & 0xf; + ac = ieee80211_ac_from_tid(tid); + } else { + ac = IEEE80211_AC_BE; + } + + ieee80211_sta_update_pending_airtime(local, sta, ac, + info->tx_time_est << 2, + true); + rcu_read_unlock(); + + } + if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) { struct ieee80211_sub_if_data *sdata; @@ -930,6 +957,17 @@ static void __ieee80211_tx_status(struct ieee80211_hw *hw, tid = qc[0] & 0xf; } + if (info->tx_time_est) { + /* Do this here to avoid the expensive lookup of the sta + * in ieee80211_report_used_skb(). + */ + ieee80211_sta_update_pending_airtime(local, sta, + ieee80211_ac_from_tid(tid), + info->tx_time_est << 2, + true); + info->tx_time_est = 0; + } + if (!acked && ieee80211_is_back_req(fc)) { u16 control; 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 ieee80211_hw *hw, struct ieee80211_tx_data tx; ieee80211_tx_result r; struct ieee80211_vif *vif = txq->vif; + u8 ac = txq->ac; + u32 airtime; WARN_ON_ONCE(softirq_count() == 0); + if (!ieee80211_txq_airtime_check(hw, txq)) + return NULL; + begin: spin_lock_bh(&fq->lock); @@ -3652,6 +3657,20 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw, } IEEE80211_SKB_CB(skb)->control.vif = vif; + + if (local->airtime_flags & AIRTIME_USE_AQL) { + airtime = ieee80211_calc_expected_tx_airtime(hw, vif, txq->sta, + skb->len); + if (airtime) { + /* We only have 10 bits in tx_time_est, so store airtime + * in increments of 4 us and clamp that to 2**10. + */ + info->tx_time_est = min_t(u32, airtime >> 2, 1 << 10); + ieee80211_sta_update_pending_airtime(local, tx.sta, ac, + airtime, false); + } + } + return skb; out: