Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933684AbcDLMRt (ORCPT ); Tue, 12 Apr 2016 08:17:49 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:42005 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932763AbcDLMRs convert rfc822-to-8bit (ORCPT ); Tue, 12 Apr 2016 08:17:48 -0400 From: "Machani, Yaniv" To: "David S. Miller" , Eric Dumazet , Neal Cardwell , Yuchung Cheng , Nandita Dukkipati , open list , "Kama, Meirav" Subject: TCP reaching to maximum throughput after a long time Thread-Topic: TCP reaching to maximum throughput after a long time Thread-Index: AdGUtUgUUC2AurLuQ6Wg1hy5fbMrTQ== Date: Tue, 12 Apr 2016 12:17:38 +0000 Message-ID: Accept-Language: en-US, he-IL Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.167.188.42] x-exclaimer-md-config: f9c360f5-3d1e-4c3c-8703-f45bf52eff6b Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2218 Lines: 47 Hi, After updating from Kernel 3.14 to Kernel 4.4 we have seen a TCP performance degradation over Wi-Fi. In 3.14 kernel, TCP got to its max throughout after less than a second, while in the 4.4 it is taking ~20-30 seconds. UDP TX/RX and TCP RX performance is as expected. We are using a Beagle Bone Black and a WiLink8 device. Were there any related changes that might cause such behavior ? Kernel configuration and sysctl values were compared, but no significant differences have been found. See a log of the behavior below : ----------------------------------------------------------- Client connecting to 10.2.46.5, TCP port 5001 TCP window size:? 320 KByte (WARNING: requested? 256 KByte) ------------------------------------------------------------ [? 3] local 10.2.46.6 port 49282 connected with 10.2.46.5 port 5001 [ ID] Interval?????? Transfer???? Bandwidth [? 3]? 0.0- 1.0 sec? 5.75 MBytes? 48.2 Mbits/sec [? 3]? 1.0- 2.0 sec? 6.50 MBytes? 54.5 Mbits/sec [? 3]? 2.0- 3.0 sec? 6.50 MBytes? 54.5 Mbits/sec [? 3]? 3.0- 4.0 sec? 6.50 MBytes? 54.5 Mbits/sec [? 3]? 4.0- 5.0 sec? 6.75 MBytes? 56.6 Mbits/sec [? 3]? 5.0- 6.0 sec? 3.38 MBytes? 28.3 Mbits/sec [? 3]? 6.0- 7.0 sec? 6.38 MBytes? 53.5 Mbits/sec [? 3]? 7.0- 8.0 sec? 6.88 MBytes? 57.7 Mbits/sec [? 3]? 8.0- 9.0 sec? 7.12 MBytes? 59.8 Mbits/sec [? 3]? 9.0-10.0 sec? 7.12 MBytes? 59.8 Mbits/sec [? 3] 10.0-11.0 sec? 7.12 MBytes? 59.8 Mbits/sec [? 3] 11.0-12.0 sec? 7.25 MBytes? 60.8 Mbits/sec [? 3] 12.0-13.0 sec? 7.12 MBytes? 59.8 Mbits/sec [? 3] 13.0-14.0 sec? 7.25 MBytes? 60.8 Mbits/sec [? 3] 14.0-15.0 sec? 7.62 MBytes? 64.0 Mbits/sec [? 3] 15.0-16.0 sec? 7.88 MBytes? 66.1 Mbits/sec [? 3] 16.0-17.0 sec? 8.12 MBytes? 68.2 Mbits/sec [? 3] 17.0-18.0 sec? 8.25 MBytes? 69.2 Mbits/sec [? 3] 18.0-19.0 sec? 8.50 MBytes? 71.3 Mbits/sec [? 3] 19.0-20.0 sec? 8.88 MBytes? 74.4 Mbits/sec [? 3] 20.0-21.0 sec? 8.75 MBytes? 73.4 Mbits/sec [? 3] 21.0-22.0 sec? 8.62 MBytes? 72.4 Mbits/sec [? 3] 22.0-23.0 sec? 8.75 MBytes? 73.4 Mbits/sec [? 3] 23.0-24.0 sec? 8.50 MBytes? 71.3 Mbits/sec [? 3] 24.0-25.0 sec? 8.62 MBytes ?72.4 Mbits/sec [? 3] 25.0-26.0 sec? 8.62 MBytes? 72.4 Mbits/sec [? 3] 26.0-27.0 sec? 8.62 MBytes? 72.4 Mbits/sec -- Thanks, Yaniv Machani