From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x236.google.com (mail-qt0-x236.google.com [IPv6:2607:f8b0:400d:c0d::236]) (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 783473BA8E for ; Wed, 25 Jul 2018 17:21:45 -0400 (EDT) Received: by mail-qt0-x236.google.com with SMTP id e19-v6so9149366qtp.8 for ; Wed, 25 Jul 2018 14:21:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :content-transfer-encoding; bh=ifT/8Iev+F0dQicwv1azkXB1BHaAeXIj6J4ysTVWPPw=; b=NiOdcBNJNxkAFiM7gZE9TJjD5r7p6rx0fzw/QpVuNpqtsljDx0gRYNwUV72p0oqe2t 2FW0MOkLlG5MfG9cYkEyMqXiaXfnoBg/Pt2IQyecKU9dipSB8vo0WQecitS90lX9MazJ /xlU9jn82mQxaInYuQg7rDAc0JjirsAsRHjsouLsAU+DZYHAEYHkWXFuMCkzv844dL/T XRsRUu5ibmTtEnH2Rl8p/SYiXLNkvwuRf8V55mIDYboqlCX2y7P53KR9fKAe3890wB3L FSzNhmXdlhOd4dSE3gqmZJDL7kxVLSEnXtrhWrh/7gEmexpWPS2fYlCfQevDge6gP0vu jM0Q== 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:content-transfer-encoding; bh=ifT/8Iev+F0dQicwv1azkXB1BHaAeXIj6J4ysTVWPPw=; b=CuDw0Qk/T9lXFK5y7AmaPfInlI0WvWYTnaLOY086l1yepws3Bf1w6fnLhikNo89iIR A4oq+oy5l1DREaaBPkyx9MGluIcrD1J0MBTC+IXdzAtZqqwad2TmK2bA3J0gnNQj4Ftg 61xH7ChvnoRav+lrJJ/DF1dLAhIOIH+FsK4AZoeZUglVNdQ721T8JQ8RtzLTEcaltjPu Dbl5PIthk7xdRbHmo69Z52ovjPtY7sSMaNLutpoDY4PyUa3Pa5hXk5K8lQjk0QhWhXpz e3s68bQIwU2z0/DoKZXljWfOJQ40jZhUTwkvMJmPbdG0Pop8+EwG9IvDzK8Rx5GwrAzF GfZg== X-Gm-Message-State: AOUpUlGgKu5Wn80qBy2Y+QLwsckltsqBGR+mbXUrnfrPC8J52eLvlC8H sCEgp8BXaE+0PaBgBJtED/j4zOGLV29a3FFgbLsz+93N X-Google-Smtp-Source: AAOMgpeVOlWsBYHy9V/g3VbiDFcZA0qkyZJsBbGPy00OFLW2lDZTbr6v/eeuya2Ce1YyGwziu86w+303+pM+3/TUgRI= X-Received: by 2002:a0c:c345:: with SMTP id j5-v6mr20279068qvi.245.1532553704688; Wed, 25 Jul 2018 14:21:44 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Dave Taht Date: Wed, 25 Jul 2018 14:21:33 -0700 Message-ID: To: Cake List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] quick patch for split_gso X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Jul 2018 21:21:45 -0000 remarkable how sensitive this is. I went back to using the rate flags (thus making this a binary option), consistently get bql of 45000 now. I want me 50usec back! Summary of tcp_nup test run 'split_gso_test_again_rate_flag_bql_auto' (at 2018-07-25 21:13:13.816743): avg median # data pts Ping (ms) ICMP : 0.85 0.82 ms 343 TCP upload avg : 235.39 235.39 Mbits/s 301 TCP upload sum : 941.57 941.57 Mbits/s 301 TCP upload::1 : 235.32 235.45 Mbits/s 276 TCP upload::2 : 235.41 235.42 Mbits/s 282 TCP upload::3 : 235.42 235.42 Mbits/s 276 TCP upload::4 : 235.42 235.43 Mbits/s 281 diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index 539c949..f77c61f 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -2572,7 +2572,7 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt, if (q->rate_bps && q->rate_bps <=3D CAKE_SPLIT_GSO_THRESHOLD) q->rate_flags |=3D CAKE_FLAG_SPLIT_GSO; else - q->rate_flags &=3D ~CAKE_FLAG_SPLIT_GSO; + q->rate_flags |=3D CAKE_FLAG_SPLIT_GSO; if (q->tins) { sch_tree_lock(sch); On Wed, Jul 25, 2018 at 2:03 PM Dave Taht wrote: > > so, I went and tested that patch. Turned out len was signed... I'd put > it in the wrong place... and the very act of doing that test at all > permutes the result. > > cake unshaped at 1gig, always splitting, ends up with a bql value of > about 42,000, full throughput, e.g. > > if (skb_is_gso(skb)) { > > ... > > avg median # data pts > Ping (ms) ICMP : 0.80 0.77 ms 341 > TCP upload avg : 235.40 235.39 Mbits/s 301 > TCP upload sum : 941.61 941.55 Mbits/s 301 > TCP upload::1 : 235.36 235.39 Mbits/s 290 > TCP upload::2 : 235.46 235.39 Mbits/s 291 > TCP upload::3 : 235.38 235.45 Mbits/s 275 > TCP upload::4 : 235.41 235.44 Mbits/s 278 > > conditionally splitting, either never or always, gives me bql of: 140852 > > if (skb_is_gso(skb) && len >=3D q->split_gso) { > > avg median # data pts > Ping (ms) ICMP : 1.64 1.71 ms 347 > TCP upload avg : 235.40 235.38 Mbits/s 301 > TCP upload sum : 941.59 941.52 Mbits/s 301 > TCP upload::1 : 235.35 235.44 Mbits/s 280 > TCP upload::2 : 235.40 235.39 Mbits/s 276 > TCP upload::3 : 235.47 235.43 Mbits/s 276 > TCP upload::4 : 235.37 235.45 Mbits/s 282 > > the cache line miss can't possibly have cost that much. (?) Guess I > have to go check the range of len. > > I WANT MY 800usec back! > > PS For giggles, I accidentally ended up using pfifo_fast for one run. > I thought I'd broke something. > > Summary of tcp_nup test run 'split_gso_test_again_len_512000_bql_auto' > (at 2018-07-25 20:51:10.533339): > > avg median # data pts > Ping (ms) ICMP : 3.32 3.59 ms 347 > TCP upload avg : 235.38 235.38 Mbits/s 301 > TCP upload sum : 941.52 941.54 Mbits/s 301 > TCP upload::1 : 152.48 150.93 Mbits/s 281 > TCP upload::2 : 152.54 150.35 Mbits/s 286 > TCP upload::3 : 483.96 491.12 Mbits/s 284 > TCP upload::4 : 152.54 150.49 Mbits/s 284 > On Tue, Jul 24, 2018 at 10:01 PM Dave Taht wrote: > > > > Ah... 1gbit, BQL at a sane size, 750 usec RTT. I guess I have to go > > compile this patch now..... > > > > > > -- > > > > Dave T=C3=A4ht > > CEO, TekLibre, LLC > > http://www.teklibre.com > > Tel: 1-669-226-2619 > > > > -- > > Dave T=C3=A4ht > CEO, TekLibre, LLC > http://www.teklibre.com > Tel: 1-669-226-2619 --=20 Dave T=C3=A4ht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619