From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 62010A920; Wed, 19 Mar 2025 19:50:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742413816; cv=none; b=S7tVdxW3VO1cQLlUaY5dYJODz4LciM+cnKf1rbjGjUQOWqZHu5rkWAvmFtxFT4JWMond/i2d8tCJ7+RFI0UzRXXlf9hcELE+TlVRR4sS4XRm0W+T+wn7txf7DgOzSUT5n2HFYkyopqz/i4WkT6Cr9sdUCvjhl4898VULr9pvKUo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742413816; c=relaxed/simple; bh=ZsbP6Tfa+TakJIzIxvjtnOXdCdqTl1sJleAd/BtH++E=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jW4pptXor4n3cr6Ut7Pbd5nZy3683r7RdFuVXUn/RapkVGpo9iH3bGu06HycHiYDyTHa/bEvMVRCYgg59Duc8L0ND8CrXPtgWRTMRHCimaPu4Wh5BR5QOPR+uqlXaBHWYjk/D1dYD/yO/1NrrtfvxIXHMEDFbQdgZ1bZY4y9MGA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=M9vZACxq; arc=none smtp.client-ip=209.85.216.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="M9vZACxq" Received: by mail-pj1-f53.google.com with SMTP id 98e67ed59e1d1-2ff6a98c638so93775a91.0; Wed, 19 Mar 2025 12:50:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1742413813; x=1743018613; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=rOCrjFT8pPG35qudWbMcGszw7gK+zyViIVYP8L9Kl0U=; b=M9vZACxqajJSaTjaKKsISGzWgQWJ+1OXTMda/0GvWz9oKB+AgDAIfkIq5Upy0RTsNM Y5A4dhttMzt/XFd5c9AYPEfj2104r7ntERHQUQT+bzJ+tydHEEhya2Q4WJ2LP7XWTfi9 jdFXY0plWLKHC1AGgMXBQ7Nx8Tn0ES1yzvtvxtkKg4N8MbsjuN9REiPxHueJYanPtgww QxjrwXoVaETpUlblIIitrVHR8JDO7lCumaA71++QC2VkrJPjci13s7IZNoTr5unFrCTZ hvBA+55/kxusYSO1ga8ACfsmiaYsByHj+U30L9gFktSwiuOu06fwzw9XKlBmZd26kAQl rn8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742413813; x=1743018613; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=rOCrjFT8pPG35qudWbMcGszw7gK+zyViIVYP8L9Kl0U=; b=Jk5Q5TcB0gRSfYyjdbpTqao3Tw+pT5ZpCElIrp6Ta3iNV0l/4IKdZHs8r61RLI9C77 m+GKdUaWnjw5M6Aqp7fotxbiZsi8D2IgEpdjNreei9FtTcUMUGo5kl8jUuZaoe0Tmyc5 W9iT0gP4rUScA6JtSIvH6Q+uYbYgxRGYDb6FoXdZGcqcyfJfDdZuPlNGYEcgs16WtmyM Ri2IrMbVhWGjshCZCMG6t++bqDjgzY8MitFOFw/ZTKHecw0sj+FRipDd9G7JlatKQYBB 2DO/V3pgOrr+X+Uz1PdIem57B4rvZPonyKTbzsNj4RnZiSzm58bF0yArPoQag0OuajFG o3DA== X-Forwarded-Encrypted: i=1; AJvYcCWMGn/n18f9tKDhvJn3Ci9HTiIizPkN60AqWxqJawMx8I6l9dxRlCqcZerdTh2+HanE3Ob55jowPZ6R4yJpVw==@vger.kernel.org X-Gm-Message-State: AOJu0YxAKCfYum/Hv2TThYzUie1/qiOoo+Bc22B9u0lQ1FGGMhudTQr0 MnIz6HYNowtSnsKQJABWDndSqKDg2ZpMcH2g9zjsgtQ/wxABXFJX X-Gm-Gg: ASbGncvv4t3Xg61vpBq2V6+YuH1DmJDzxcBL4nl/RTOn+n/r7wEkq9VotKUyPY5BZOK vmroLIgLeO3acSWTE54h8OprSaPesr5pI3kbqF1378aQK6nM2wA4wefxIxXYXw6yC9n4FSmZ4Os 7VMY4wJgKdvR5xfdSq43qb36ZQUAr7eS2LwDkAm/EmziMIW9AsHFhBUsXnttiT4R9Fy2jNiyd2v F0J9BRtebGNQy8bKeZrHfTPzfgVCZGgUlwf299LPjV7Ez9gDlDV+VApH8rgPH27UW6+RXPodRlq X0fVCankD4jyJn8MU1LhEtD3GIKOMlwwueMXZccOLutCZRcJ X-Google-Smtp-Source: AGHT+IG60Nv4IyKEwP5oBlRZaeZbJxv+QDR41nvkKlo0pUCU9APXKlZxdx1aNv2TezDy79IPBTgtig== X-Received: by 2002:a17:90b:3d10:b0:301:1c11:aa83 with SMTP id 98e67ed59e1d1-301be1f8caamr5530982a91.28.1742413813406; Wed, 19 Mar 2025 12:50:13 -0700 (PDT) Received: from [10.100.121.195] ([152.193.78.90]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-301bf58af67sm2087269a91.17.2025.03.19.12.50.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 Mar 2025 12:50:12 -0700 (PDT) Message-ID: <792bd4a3-4e51-49ef-ba55-1922505b1c8d@gmail.com> Date: Wed, 19 Mar 2025 12:50:10 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH] mac80211: clip ADDBA instead of bailing out To: alexandre.ferrieux@orange.com, Alexandre Ferrieux , linux-wireless@vger.kernel.org Cc: Linux Kernel Network Developers , Johannes Berg References: <20250317163902.1893378-1-sashal@kernel.org> <20250317163902.1893378-2-sashal@kernel.org> <69c63a19-5419-4bbe-858f-6ca100345a28@orange.com> <1560b292-6366-4588-ad4d-654377613b84@gmail.com> <2b5c91c6-49db-42bb-803c-c01dc785e1f1@orange.com> Content-Language: en-US From: James Prestwood In-Reply-To: <2b5c91c6-49db-42bb-803c-c01dc785e1f1@orange.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Alexandre, On 3/19/25 7:18 AM, alexandre.ferrieux@orange.com wrote: > Hi James, > > There is roughly a 8x slowdown :} > I got these numbers from the colleagues who detected the issue > > - physical available bandwidth 1.733 Gbps (as per iwconfig) > - ADDBA offer size=256 > - effective bandwidth observed 1.2Gbps with accept-and-clip-ADDBA (size=64) > - vs. 150 Mbps with reject-ADDBA Fwiw I didn't see any difference in throughput with and without this patch. We do use wifi 6/6e APs and wifi 5 clients (ath10k), but I suspect it has something to do with our configuration not taking full advantage of 6/6e speeds, so the APs may not be proposing an ADDBA size that the client rejects. But I'll keep this in mind if we ever notice the behavior. Overall though I didn't observe and regression-type behavior. Thanks, James > > Note, as a Wifi rookie it is not immediately obvious to me how the semantics of > ack aggregation would interfere with broadcast actions, as ADDBA are supposedly > unicast. But you're the expert :) > > > > On 19/03/2025 14:21, James Prestwood wrote: >> -------------------------------------------------------------------------------------------------------------- >> CAUTION : This email originated outside the company. Do not click on any links or open attachments unless you are expecting them from the sender. >> >> ATTENTION : Cet e-mail provient de l'extérieur de l'entreprise. Ne cliquez pas sur les liens ou n'ouvrez pas les pièces jointes à moins de connaitre l'expéditeur. >> -------------------------------------------------------------------------------------------------------------- >> >> Hi Alexandre, >> >> On 3/19/25 3:58 AM, Alexandre Ferrieux wrote: >>> When a Linux Wifi{4,5} device talks to a Wifi6 AP, if the AP proposes a Block >>> Acknowledgement aggregation size (ADDBA) exceeding its expectations, the code in >>> mac80211 just bails out, rejecting the aggregation. This yields a big >>> performance penalty on the ack path, which is observable in comparison with >>> other OSes (Windows and MacOS) which "play smarter" and accept the proposal with >>> a "clipped" size. >> Out of curiosity do you have any performance numbers for this, like >> Linux vs Windows vs MacOS? We ran into a significant performance hit >> after I added multicast RX support on ath10k (after ~30 clients were on >> the same channel). After looking into the pcaps we saw many ADDBA >> failures and ultimately had to disable multicast RX. I want to give this >> patch a try either way, but I was curious if you had any data on >> performance improvements. >>> A typical scenario would be: >>> >>> AP -> Device : ADDBA_request(size=256) >>> >>> Current Linux reaction: >>> >>> Device -> AP : ADDBA_reply(failure) >>> >>> Other OSes reaction: >>> >>> Device -> AP : ADDBA_reply(size=64) >>> >>> Note that the IEEE802.11 standard allows for both reactions, but it sounds >>> really suboptimal to be bailing out instead of clipping. The patch below does >>> the latter. >>> >>> Signed-off-by: Alexandre Ferrieux >>> --- >>> >>> diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c >>> index f3fbe5a4395e..264dad847842 100644 >>> --- a/net/mac80211/agg-rx.c >>> +++ b/net/mac80211/agg-rx.c >>> @@ -317,18 +317,20 @@ void __ieee80211_start_rx_ba_session(struct sta_info *sta, >>> max_buf_size = IEEE80211_MAX_AMPDU_BUF_HT; >>> >>> /* sanity check for incoming parameters: >>> - * check if configuration can support the BA policy >>> - * and if buffer size does not exceeds max value */ >>> + * check if configuration can support the BA policy */ >>> /* XXX: check own ht delayed BA capability?? */ >>> if (((ba_policy != 1) && >>> - (!(sta->sta.deflink.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) || >>> - (buf_size > max_buf_size)) { >>> - status = WLAN_STATUS_INVALID_QOS_PARAM; >>> + (!(sta->sta.deflink.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA)))) { >>> + status = WLAN_STATUS_INVALID_QOS_PARAM; >>> ht_dbg_ratelimited(sta->sdata, >>> "AddBA Req with bad params from %pM on tid >>> %u. policy %d, buffer size %d\n", >>> sta->sta.addr, tid, ba_policy, buf_size); >>> goto end; >>> } >>> + if (buf_size > max_buf_size) { >>> + buf_size = max_buf_size ; // Clip instead of bailing out >>> + } >>> + >>> /* determine default buffer size */ >>> if (buf_size == 0) >>> buf_size = max_buf_size; >>> >>> > ____________________________________________________________________________________________________________ > Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc > pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler > a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration, > Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci. > > This message and its attachments may contain confidential or privileged information that may be protected by law; > they should not be distributed, used or copied without authorisation. > If you have received this email in error, please notify the sender and delete this message and its attachments. > As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified. > Thank you.