From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-x144.google.com (mail-lf1-x144.google.com [IPv6:2a00:1450:4864:20::144]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id AFF0E3B29E for ; Tue, 3 Dec 2019 14:02:57 -0500 (EST) Received: by mail-lf1-x144.google.com with SMTP id r14so3914188lfm.5 for ; Tue, 03 Dec 2019 11:02:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=WKfh6GWqcaSVgesRgdbFaj17CDDjaivkWCoA/zzVuzk=; b=A6OMwBIPYhKqtUoc0aqT172eH5LSzXX/5Yj6kINNSYyyohieCqtm8KN9j84YPz3twY NYJjl0S/O3YKRiTtOQZnMlm5u55uHlRnRVnynJ+1trJlHL6XAhvFqR45LIIpOGew51S5 LP/QchwQaGmpcNQv9r1ZTOWJaojXMcsySaFo0SF7RgKhn7IyZifuKPZFekTe+hes4TPf zP9GY6RqiVCL/+LE6h1uD07DIzKWuWhBstKhFVnVbJWEzYQnjdyiYXtVJx2UDLxuxntu KKvFWwDftVdkqChyV4pZHjHezUBTPsxMBKX/UICNrkycZv0MbZwrGZnkpccFYaDvlT6q nIwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=WKfh6GWqcaSVgesRgdbFaj17CDDjaivkWCoA/zzVuzk=; b=XIInTTPYLoeA/jujo1nUuIY4V7GZcUmzvq1N/Q2CGX2P57V62a1dmNIcDk5cWUerV2 8WuN3iZtT94ZtmM4gpLmiQh1n7FrsiAgrG7GM+izxW2Y1/OkRh7ee422r96eAw2i9TOg +pB8oLWqmrlYybABRtelhMDk6sKNuvc233GsOczK2+crw047HPbGd4L4xuvGRqNWD2HK smrac9R6gE9x8e3Y8VtfdkuEyEYODymC+Fj+1fJl4MkFjmpyYSdIoSPXZ5Rq51q1vYYA JHlq9/t5rJmL02ah4bLgsohDMYc6/ay77FKy0W1FH1gd9AQQ1D1CRW8zQvf4WoVj3soP YBnA== X-Gm-Message-State: APjAAAUp+YZaG8xKGUqKgc+dWTaQp7KVQ32TIcLuyPcKddHGHqx6ngGl noIFQ+ufSJIpBdHv2hG6pMu60x/kL5bhvfAEwh4ilw== X-Google-Smtp-Source: APXvYqwitBPEhqoOUjaebGsAJwes+hxPAol9nfWGNbmaAJN5OleoZyKQjuozpKuBKgirVI2D/UnH7s7CF11QUYliVoA= X-Received: by 2002:ac2:5c4a:: with SMTP id s10mr3647289lfp.88.1575399775967; Tue, 03 Dec 2019 11:02:55 -0800 (PST) MIME-Version: 1.0 References: <20191115014846.126007-1-kyan@google.com> <8736eiam8f.fsf@toke.dk> <87a78p8rz7.fsf@toke.dk> <87muco5gv5.fsf@toke.dk> <87eexvyoy8.fsf@toke.dk> <878so2m5gp.fsf@nemesis.taht.net> In-Reply-To: <878so2m5gp.fsf@nemesis.taht.net> From: Kan Yan Date: Tue, 3 Dec 2019 11:02:44 -0800 Message-ID: Subject: Re: [Make-wifi-fast] [PATCH v8 0/2] Implement Airtime-based Queue Limit (AQL) To: Dave Taht Cc: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , Rajkumar Manoharan , Kevin Hayes , Make-Wifi-fast , linux-wireless , Yibo Zhao , John Crispin , Johannes Berg , Lorenzo Bianconi , Felix Fietkau Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-List-Received-Date: Tue, 03 Dec 2019 19:02:58 -0000 Dave Taht writes: > I hope to take a close look at the iwl ax200 chips soon. Unless > someone beats me to it. Can we get these sort of stats out of it? Here is a patch for the trace event I used to get the sojourn time: https://drive.google.com/open?id=3D1Mq8BO_kcneXBqf3m5Rz5xhEMj9jNbcJv Toke H=C3=B8iland-J=C3=B8rgensen writes: > While you're running tests, could you do one with the target changed to > 10ms, just to see what it looks like? Both sojourn time values and > throughput would be interesting here, of course. Apologize for the late reply. Here is the test results with target set to 1= 0ms. The trace for the sojourn time: https://drive.google.com/open?id=3D1MEy_wbKKdl22yF17hZaGzpv3uOz6orTi Flent test for 20 ms target time vs 10 ms target time: https://drive.google.com/open?id=3D1leIWe0-L0XE78eFvlmRJlNmYgbpoH8xZ The sojourn time measured during throughput test with a relative good 5G connection has mean value around 11 ms, pretty close to the 10 ms target. A smaller CoDel "target" time could help reduce latency, but it may drop packets too aggressively for stations with low data rate and hurts throughput, as shown in one of the tests with 2.4 GHz client. Overall, I think AQL and fq_codel works well, at least with ath10k. The current target value of 20 ms is a reasonable default. It is relatively conservative that helps stations with weak signal to maintain stable throughput. Although, a debugfs entry that allows runtime adjustment of target value could be useful. On Tue, Nov 26, 2019 at 6:13 PM Dave Taht wrote: > > Toke H=C3=B8iland-J=C3=B8rgensen writes: > > > Kan Yan writes: > > > >>> Yeah, bpftrace can be a bit of a pain to get running; but it may be > >>> worth the investment longer term as well. It really is quite useful! = :) > >> > >> My attempt to build bpftrace didn't work out, so I just got the > >> sojourn time using old fashioned trace event. > >> The raw trace, parsed data in csv format and plots can be found here: > >> https://drive.google.com/open?id=3D1Mg_wHu7elYAdkXz4u--42qGCVE1nrILV > >> > >> All tests are done with 2 TCP download sessions that oversubscribed > >> the link bandwidth. > >> With AQL on, the mean sojourn time about ~20000us, matches the default > >> codel "target". > > > > Yeah, since CoDel is trying to control the latency to 20ms, it makes > > sense that the value is clustered around that. That means that the > > algorithm is working as they're supposed to :) > > > > While you're running tests, could you do one with the target changed to > > 10ms, just to see what it looks like? Both sojourn time values and > > throughput would be interesting here, of course. > > > >> With AQL off, the mean sojourn time is less than 4us even the latency > >> is off the charts, just as we expected that fd_codel with mac80211 > >> alone is not effective for drivers with deep firmware/hardware queues > > I hope to take a close look at the iwl ax200 chips soon. Unless > someone beats me to it. Can we get these sort of stats out of it? > > Has anyone looked at the marvell chips of late? > > > > > Yup, also kinda expected; but another good way to visualise the impact. > > Nice! > > > > -Toke > > > > _______________________________________________ > > Make-wifi-fast mailing list > > Make-wifi-fast@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/make-wifi-fast