From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-x231.google.com (mail-ob0-x231.google.com [IPv6:2607:f8b0:4003:c01::231]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 38F3921F3A5 for ; Thu, 2 Apr 2015 21:11:37 -0700 (PDT) Received: by obbec2 with SMTP id ec2so156787593obb.3 for ; Thu, 02 Apr 2015 21:11:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=AxeFJWU0UtpCO2gRFCZgb9Uk0M3n7SBY7kKzFTy7BT0=; b=ttj7UPFCq9f7dGw4eEhxfMBu276Fl4wEVLsozRX/mDhjM2OEKNx0dkueoVrss+QmaL W1zrR+JMiY3QKU0KZ2ITbGeqR0TdrH/whgya70dmFmZyklJFiinpQUrH4kG6biyoYbD4 ihE1z3+qGoaEaVdaAevle2ywgD2maL/75nV3I8z+q0sNmqB52ZeFy5ytp6MTp0Rjby2g s+AiPmur7O6Jwj2ke9VXs3oTrS6dxGIuj7RzrKCfa5h0u30UlDmpT7AeRRsZb4iiiVIS 0Pm3P6VLfA4GvrN5bgvejWS+lGmWLn8MDAwXyGPBphnXXGytYGA8TdjPdX7DK3Mx1vKl 7saA== MIME-Version: 1.0 X-Received: by 10.60.98.2 with SMTP id ee2mr705615oeb.39.1428034296909; Thu, 02 Apr 2015 21:11:36 -0700 (PDT) Received: by 10.202.51.66 with HTTP; Thu, 2 Apr 2015 21:11:36 -0700 (PDT) Date: Thu, 2 Apr 2015 21:11:36 -0700 Message-ID: From: Dave Taht To: "cerowrt-devel@lists.bufferbloat.net" , Jesper Dangaard Brouer , Felix Fietkau , Imre Kaloz , John Crispin Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Cerowrt-devel] =?utf-8?q?today=C2=B4s_archer_c7v2_testing=3A_xmi?= =?utf-8?q?t=5Fmore_loses_vs_stock?= X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Apr 2015 04:12:06 -0000 today I finally had a chance to benchmark xmit_more enablement on the archer c7v2. I enabled xmit_more support in the driver, and also modified the NAPI settings to only fire every 32 packets instead of 64. (I had done a prior run on the wndr with NAPI setting of 64 that was worse) More netperf-wrapper data than you can shake a stick at here: http://snapon.lab.bufferbloat.net/~d/archer_xmit_more_tests.tgz Previous test runs for the wndr3800 here: http://snapon.lab.bufferbloat.net/~d/xmit_more_3800.tgz A) on rrul it was a slight lose, in an odd way. Where with the default settings, I would see packets queue up in the cake3 qdisc and be smartly managed there, with that setting I saw nothing queue up in the cake3 qdiscs, less throughput, and more latency. http://snapon.lab.bufferbloat.net/~d/xmit_more_comparison_archer.png [1] My guess here was that this change to the overall flow balance inside the r= outer pushed all drops to the rx ring. B) but on the tcp_upload test xmit_more was quite obviously a lose: http://snapon.lab.bufferbloat.net/~d/xmit_more_tcp_upload.svg ... So in summary I think that xmit_more is of value when the cpu is sufficiently fast to stuff in and get bits at line rate, but not of value on these weak embedded cpus, where the shorter the code path, the better off you are. In my next build I will try disabling it entirely. I am open to other suggestions. C) But - per the graph above - also hostapd running all the time as it presently does for no sane reason I can discern, costs 80mbits of throughput, and cake3 has quite a ways to go until it is as fast as fq_codel. (NOT planning on worrying about speeding it up for a while! Am happy to keep it targetted at being faster than HTB at non-line rates, make it more correct, etc, etc. - line rate is not the target... stay calm... no premature optimizations please...) cake3 looks quite good vs htb+fq_codel, there is some netperf-wrapper data in there on that, also. D) It was comforting to see ipv6 forwarding rates actually slightly higher than natted IPv4 on these tests, with the unaligned access hacks turned off, and compiled for this specific processor. [1] I also fiddled with reducing the tx ring to 8, with "interesting" resul= ts. --=20 Dave T=C3=A4ht Let's make wifi fast, less jittery and reliable again! https://plus.google.com/u/0/107942175615993706558/posts/TVX3o84jjmb