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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS autolearn=ham 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 95BA3C282CE for ; Sun, 14 Apr 2019 09:44:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E829218D3 for ; Sun, 14 Apr 2019 09:44:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="IdFVNxsX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726159AbfDNJoW (ORCPT ); Sun, 14 Apr 2019 05:44:22 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:43578 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725797AbfDNJoV (ORCPT ); Sun, 14 Apr 2019 05:44:21 -0400 Received: by mail-ed1-f68.google.com with SMTP id j20so1791410edq.10 for ; Sun, 14 Apr 2019 02:44:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=IiSsptnnyZ9bqezfXcL3CGfC0PcZy8wJum/lZcgYTXw=; b=IdFVNxsX/tQ4KaEemI35DCjxv2Q1qOExoNVW7hNo9WU9ATPqJ0hAEAHVFB22xhD4NW 0QOHRArpsyKZP5RB0NzZTs/VRVpQ1KKS93UuQj7NvBFZyxP0+mG5klgh0ZT+ebgTmY0Z fXO2NuXqusJzrnWY9K0nMmZgPC3tVK0DKUDWg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=IiSsptnnyZ9bqezfXcL3CGfC0PcZy8wJum/lZcgYTXw=; b=Ps4lAIo6Q21//g1KMj6L7haD/aMn5Ro6ecH+ZPrWi2U5ohWYPKGn8OXYyKgZOjSf37 NYc5HJmKru0OhDN2+lerl8TVo/U2koazqVtZ6s/2gICYKgut/SOC82ktXTENb29gJJd5 DOhVg23r3k6i3qXx1F2BPyhe82NvuCEjGdO/cgiGPXbXcJKaZz3cVjGf6UckM7woMSiB gdjP/Mm60QP+E5okOFqw5AA9cE4uVyLiMOebn4Z+4wZcLLo2YYU8QJ/86Hq9D3aB1Ks2 m7E8rf3SnZwUpWSbr2V8tJ+dBIUg8v1oghyNhvKa6pTVBYf8lYonaL3VNxbSwLQjSxng F4GA== X-Gm-Message-State: APjAAAVSjHfGQY1HkOaMTsOUTfaQEWjDeZqxU4KYlGCv/yWf7oS5DJKt SvmwgnAFyoNHtRqw+bnl2AbjFQ== X-Google-Smtp-Source: APXvYqy52Guyko5P39KimqDRqQ3I/nOrJ//PqPEb4+vK/eMuxWOwCiCERuCS6aRgL4gwBYxck5e/bQ== X-Received: by 2002:a50:ac76:: with SMTP id w51mr3442677edc.13.1555235059597; Sun, 14 Apr 2019 02:44:19 -0700 (PDT) Received: from [192.168.178.129] (f140230.upc-f.chello.nl. [80.56.140.230]) by smtp.gmail.com with ESMTPSA id a25sm5381685edr.94.2019.04.14.02.44.17 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 14 Apr 2019 02:44:18 -0700 (PDT) Subject: Re: [PATCH 5/5] mac80211: set NETIF_F_LLTX when using intermediate tx queues To: =?UTF-8?Q?Toke_H=c3=b8iland-J=c3=b8rgensen?= , Felix Fietkau , linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net, Herbert Xu References: <20190316170634.13125-1-nbd@nbd.name> <20190316170634.13125-5-nbd@nbd.name> <87sgvmvg9g.fsf@toke.dk> From: Arend Van Spriel Message-ID: <773e4dff-29fd-22b4-e4bc-cd5a94c66dc2@broadcom.com> Date: Sun, 14 Apr 2019 11:44:17 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <87sgvmvg9g.fsf@toke.dk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org + Herbert On 3/16/2019 7:14 PM, Toke Høiland-Jørgensen wrote: > Felix Fietkau writes: > >> When using iTXQ, tx sequence number allocation and statistics are run at >> dequeue time. Because of that, it is safe to enable NETIF_F_LLTX, which >> allows tx handlers to run on multiple CPUs in parallel. > > Cool, didn't know about that flag. It is water under the bridge as this patch got applied already, but I stumbled upon it just recently and didn't know about that flag either. So I looked for more information about it and found the definition [1], but the comment seemed important enough to send this reply. NETIF_F_LLTX_BIT, /* LockLess TX - deprecated. Please */ /* do not use LLTX in new drivers */ Here is the commit that marked it deprecated: commit e24eb521fbf2a350ce879dfc1d8e56d4ffa2aa22 Author: Christian Borntraeger Date: Tue Sep 25 19:42:02 2007 -0700 [NET]: note that NETIF_F_LLTX is deprecated So I am not sure we should really do this in mac80211. Maybe Herbert can comment although it has been over a decade ago. Regards, Arend [1] https://elixir.bootlin.com/linux/latest/source/include/linux/netdev_features.h#L32