From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8016AC282E1 for ; Thu, 25 Apr 2019 08:49:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D453218AD for ; Thu, 25 Apr 2019 08:49:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727535AbfDYIts (ORCPT ); Thu, 25 Apr 2019 04:49:48 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:55690 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725965AbfDYIts (ORCPT ); Thu, 25 Apr 2019 04:49:48 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1hJa4d-0005ey-HY; Thu, 25 Apr 2019 10:49:43 +0200 Message-ID: Subject: Re: [PATCH 5/5] mac80211: set NETIF_F_LLTX when using intermediate tx queues From: Johannes Berg To: Herbert Xu Cc: Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen?= , Arend Van Spriel , Felix Fietkau , linux-wireless@vger.kernel.org, Eric Dumazet , netdev@vger.kernel.org Date: Thu, 25 Apr 2019 10:49:42 +0200 In-Reply-To: <20190425084428.poni4y7mqox5up5t@gondor.apana.org.au> References: <95f86cf69dee05a176625925657cf0df0e97b5c9.camel@sipsolutions.net> <20190416093707.dtlwcmitzqopaeaw@gondor.apana.org.au> <20190416131346.u2uolljlrd5t2jro@gondor.apana.org.au> <87wojut7f7.fsf@toke.dk> <20190417033834.ep6t7r6ttvjek5g7@gondor.apana.org.au> <87tvexrnxm.fsf@toke.dk> <99da695257304d32b65e2db8b7ada06759087c90.camel@sipsolutions.net> <20190425083558.p3kqodaawr2jcfhr@gondor.apana.org.au> <0190c32f3d861d9d7a783090653645c5ae3a7fa3.camel@sipsolutions.net> <20190425084428.poni4y7mqox5up5t@gondor.apana.org.au> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-2.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Thu, 2019-04-25 at 16:44 +0800, Herbert Xu wrote: > On Thu, Apr 25, 2019 at 10:39:52AM +0200, Johannes Berg wrote: > > > > Yes, that's what I meant, it can only ever return NET_XMIT_SUCCESS or > > NET_XMIT_CN. This will not trigger the code you mentioned before though. > > You are right that it does not. However, the fact that this > congestion indication is lost is a bug rather than a feature. You can argue that way, I guess. However, *any* queue management algorithm that doesn't *solely* employ tail drops will necessarily behave this way. I would argue that you get better queue management if you don't solely rely on tail drops, so I'd rather pick better queue management than this (relatively obscure) congestion notification. The more commonly relevant socket buffer size will work for both. johannes