Return-path: Received: from vmail02-lax.tokbox.com ([72.51.46.97]:42516 "EHLO ns.stoaks-software.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750794Ab2LCSV7 convert rfc822-to-8bit (ORCPT ); Mon, 3 Dec 2012 13:21:59 -0500 Reply-To: From: "Paul Stoaks" To: "'Georgiewskiy Yuriy'" , "'Chaoxing Lin'" Cc: References: In-Reply-To: Subject: RE: help: 802.11s bad performance with 802.11n enabled Date: Mon, 3 Dec 2012 10:21:56 -0800 Message-ID: <005601cdd183$14666bf0$3d3343d0$@com> (sfid-20121203_192203_296077_96868BC7) MIME-Version: 1.0 Content-Type: text/plain; charset="KOI8-R" Sender: linux-wireless-owner@vger.kernel.org List-ID: What kind of traffic are you pushing through (packet sizes?) Are they fixed size, fixed rate, or ...? Paul -----Original Message----- From: linux-wireless-owner@vger.kernel.org [mailto:linux-wireless-owner@vger.kernel.org] On Behalf Of Georgiewskiy Yuriy Sent: Monday, December 03, 2012 7:44 AM To: Chaoxing Lin Cc: linux-wireless@vger.kernel.org Subject: RE: help: 802.11s bad performance with 802.11n enabled On 2012-12-03 14:56 -0000, Chaoxing Lin wrote Georgiewskiy Yuriy: CL>CL>For experiment, I changed ath9k driver to disable 802.11n packet aggregation. The network becomes much better. CL>CL>It's as stable as running 802.11a only mode. CL>CL>So it seems that the aggregation plays a big role in in-stability of 802.11s network with 802.11n. CL>CL>Any one has any idea why? CL> CL>Can you post a patch? i want test this too. CL> CL>The change is easy CL>In ath9k/init.c CL>Function ath9k_set_hw_capab() CL>Replace below CL> if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_HT) CL> hw->flags |= IEEE80211_HW_AMPDU_AGGREGATION; with CL> hw->flags &= ~IEEE80211_HW_AMPDU_AGGREGATION; On first look in my case disabled aggregation reduces packet loss, link is more reliable, but it's also drop throughput to 15-20 Mbits/sec from about ~50 with aggregation enabled. C ????????? With Best Regards ???????????? ????. Georgiewskiy Yuriy +7 4872 711666 +7 4872 711666 ???? +7 4872 711143 fax +7 4872 711143 ???????? ??? "?? ?? ??????" IT Service Ltd http://nkoort.ru http://nkoort.ru JID: GHhost@icf.org.ru JID: GHhost@icf.org.ru YG129-RIPE YG129-RIPE