Return-path: Received: from wa-out-1112.google.com ([209.85.146.178]:24925 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752428AbYGAKEG (ORCPT ); Tue, 1 Jul 2008 06:04:06 -0400 Received: by wa-out-1112.google.com with SMTP id j37so1439780waf.23 for ; Tue, 01 Jul 2008 03:04:05 -0700 (PDT) Message-ID: <1ba2fa240807010304q2a30aae7v888d3be54eaeb47b@mail.gmail.com> (sfid-20080701_120417_571800_BEDC4CEA) Date: Tue, 1 Jul 2008 13:04:05 +0300 From: "Tomas Winkler" To: "Luis R. Rodriguez" Subject: Re: compat-wireless high packet loss. Cc: "Johannes Berg" , "Guy Cohen" , "David Miller" , "John W. Linville" , "Linux Wireless" , "Emmanuel Grumbach" , "Patrick McHardy" In-Reply-To: <43e72e890807010229m12b7382ft8675924cac923c7b@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <1ba2fa240806261603g30c3e757y9166c2f9e05f7666@mail.gmail.com> <247d6d340806282323v3192ead8v149359e482375991@mail.gmail.com> <1214824149.5507.36.camel@johannes.berg> <1ba2fa240806300429l679f1568k584143b448455594@mail.gmail.com> <43e72e890807010229m12b7382ft8675924cac923c7b@mail.gmail.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, Jul 1, 2008 at 12:29 PM, Luis R. Rodriguez wrote: > On Mon, Jun 30, 2008 at 4:29 AM, Tomas Winkler wrote: >> On Mon, Jun 30, 2008 at 2:09 PM, Johannes Berg >> wrote: >>> On Sun, 2008-06-29 at 09:23 +0300, Guy Cohen wrote: >>>> More info on the issue.. The problem is with TX of unrestrained UDP >>>> stream, when the traffic generated at the application layer is larger >>>> than the link can pass. With kernel 2.6.26-* the traffic is restrained >>>> when the TX FIFOs gets full while in 2.6.25.* frames are dropped at >>>> some layer. It seems that the drop happens after the IP fragmentation >>>> step at the stack. >>> >>> does compat use multiqueue now? if not, look in the mac80211 fake mq >>> code. >> >> 2.6.25 has a real mq > > We only use fake mq support for kernels <= 2.6.22 as 2.6.23 added > support for MQ. Also if your 2.6.23 doesn't have MQ it will warn you. We did some more black box testing and this is happening only in UDP streaming. TCP is okay. Again this bug is not present in 2.6.26-rc3 and up. Thanks Tomas