Return-path: Received: from mail-ey0-f174.google.com ([209.85.215.174]:35440 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755841Ab0GZXgs convert rfc822-to-8bit (ORCPT ); Mon, 26 Jul 2010 19:36:48 -0400 Received: by eya25 with SMTP id 25so585661eya.19 for ; Mon, 26 Jul 2010 16:36:47 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <4C4791AF.8040909@openwrt.org> Date: Tue, 27 Jul 2010 01:36:46 +0200 Message-ID: Subject: Re: [ath9k-devel] ath9k: performance regressions / tx semi-stuck somehow From: =?ISO-8859-1?Q?Bj=F6rn_Smedman?= To: Felix Fietkau Cc: ath9k-devel@lists.ath9k.org, linux-wireless Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: 2010/7/23 Bj?rn Smedman : > 2010/7/22 Felix Fietkau : >> On 2010-07-22 12:17 AM, Bj?rn Smedman wrote: >>> I just tried out compat-wireless-2010-07-16 on AR913x (with >>> openwrt/trunk@r22321) and saw some weird performance problems. >>> >> Could you please try if the earlier version that was in OpenWrt >> (2010-07-06) has the same issues? I had some trouble reproducing this but now I feel convinced that this performance issue was caused by interference, although I think ath9k could do a better job in difficult radio environments. Note how downstream throughput goes from ~55 Mbps down to around 3 Mbps. Nothing is moved in this experiment. bjorn-smedmans-macbook-2:~ bjornsmedman$ iperf -w 256K -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 256 KByte ------------------------------------------------------------ [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 58060 [ ID] Interval Transfer Bandwidth [ 4] 0.0-30.0 sec 194 MBytes 54.1 Mbits/sec [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 58926 [ ID] Interval Transfer Bandwidth [ 4] 0.0-30.0 sec 203 MBytes 56.6 Mbits/sec [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 58990 [ ID] Interval Transfer Bandwidth [ 4] 0.0-30.0 sec 190 MBytes 53.2 Mbits/sec [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 59236 [ ID] Interval Transfer Bandwidth [ 4] 0.0-30.0 sec 189 MBytes 52.8 Mbits/sec [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 64327 [Some interference source probably comes in here] [ ID] Interval Transfer Bandwidth [ 4] 0.0-34.5 sec 5.64 MBytes 1.37 Mbits/sec [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 64424 [ ID] Interval Transfer Bandwidth [ 4] 0.0-30.3 sec 8.06 MBytes 2.23 Mbits/sec [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 64625 [ ID] Interval Transfer Bandwidth [ 4] 0.0-31.3 sec 13.6 MBytes 3.64 Mbits/sec If I then switch the AP channel (from 1 to 11) performance is looking good again: bjorn-smedmans-macbook-2:~ bjornsmedman$ iperf -w 256K -s ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 256 KByte ------------------------------------------------------------ [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 55550 [ ID] Interval Transfer Bandwidth [ 4] 0.0-120.0 sec 621 MBytes 43.4 Mbits/sec [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 55562 [ ID] Interval Transfer Bandwidth [ 4] 0.0-120.0 sec 764 MBytes 53.4 Mbits/sec [ 4] local 192.168.78.119 port 5001 connected with 192.168.78.211 port 55568 [ ID] Interval Transfer Bandwidth [ 4] 0.0-10.0 sec 68.1 MBytes 56.9 Mbits/sec /Bj?rn