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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 62238C3F2D2 for ; Fri, 28 Feb 2020 10:16:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B106246B0 for ; Fri, 28 Feb 2020 10:16:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="I25S4OL3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726890AbgB1KQo (ORCPT ); Fri, 28 Feb 2020 05:16:44 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:34500 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726063AbgB1KQo (ORCPT ); Fri, 28 Feb 2020 05:16:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582885002; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eVoGLbtnYzXWlmc48w0t/0qrnxkTvQefS/f9aokidUA=; b=I25S4OL3W5DO/IKq0F2mP5ltH69hg4MKpfS+/8+cj9ye+vJVfpZKZ3PcJowdeH2peYxrgQ TIGm6/brjWVvb3Ym84ZzqiP1oqg6x0rvu9XTZovG1BsMPzDGTXNuDFEkL0B5Xcvg2eP9cp oRP9U04JZOtqZ+W7AwuM83S+qBSv/+k= Received: from mail-lf1-f72.google.com (mail-lf1-f72.google.com [209.85.167.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-224-tuTwk0sjNwapV7gtUNxV2g-1; Fri, 28 Feb 2020 05:16:40 -0500 X-MC-Unique: tuTwk0sjNwapV7gtUNxV2g-1 Received: by mail-lf1-f72.google.com with SMTP id r24so341826lfi.23 for ; Fri, 28 Feb 2020 02:16:39 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=eVoGLbtnYzXWlmc48w0t/0qrnxkTvQefS/f9aokidUA=; b=KK2xjndRNeaYyPIx2TYh/4k/cPiiyhZAtZRAF4XJLlRzLCHajHN4WAcg5FZVOsl1LR StACxUYIg45YHKflgqPZ3D1GqPIQ9vi9UdGPCVgVBMLROD8BYpcn6SZ9kyFa10SS13IB PSVFlUBgJmidGfGnmoXwo2FH7K31ddh5dYYJy4xUhgZba5+HOnirOLeJbiLZHVNhRl9C ZKdHo+NQW0KOMrRBTZBj0/LfLgEgxR4DCvimncKV+VSpVc+m/NvKZH+0dFDv1ldDn73J /Ek6lHwpFAd+pUXv5v/1gg1yB44EIAWdeRxVp6b3lTTLhsjj6ZNZdpQbtsxt1B+TYnhL 9Fkg== X-Gm-Message-State: ANhLgQ3t01ku/wZKXep2QcRWr2PE3lpXS4zwV5m4bPH1I/eKLNvSpDps uP61xXJS6bSyvKYusA8RKKjBKQl0T+m6cHsa/+CgIbRChCybnQXnRVpdToKbQmMXXcGDowgL2Hw k9NYVtYrT7l9I87RP X-Received: by 2002:a19:7d04:: with SMTP id y4mr2282663lfc.111.1582884998571; Fri, 28 Feb 2020 02:16:38 -0800 (PST) X-Google-Smtp-Source: ADFU+vvXO5F7cH4hg0ivZxLRqZGLTBjzmF9Evdui+BrIiVguCGiV5KpQodnEEMWnFVLVq1UTeuRPKQ== X-Received: by 2002:a19:7d04:: with SMTP id y4mr2282655lfc.111.1582884998373; Fri, 28 Feb 2020 02:16:38 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id 19sm4543665lfp.86.2020.02.28.02.16.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Feb 2020 02:16:37 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id AC741180362; Fri, 28 Feb 2020 11:16:36 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Luigi Rizzo , netdev@vger.kernel.org, davem@davemloft.net, hawk@kernel.org, sameehj@amazon.com Cc: linux-kernel@vger.kernel.org, Luigi Rizzo Subject: Re: [PATCH v3 net-next] netdev attribute to control xdpgeneric skb linearization In-Reply-To: <20200227173428.5298-1-lrizzo@google.com> References: <20200227173428.5298-1-lrizzo@google.com> X-Clacks-Overhead: GNU Terry Pratchett Date: Fri, 28 Feb 2020 11:16:36 +0100 Message-ID: <87h7zbuid7.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Luigi Rizzo writes: > Add a netdevice flag to control skb linearization in generic xdp mode. > > The attribute can be modified through > /sys/class/net//xdp_linearize > The default is 1 (on) Calling it just 'xdp_linearize' implies (to me) that it also affects driver-mode XDP. So maybe generic_xdp_linearize ? [...] > + > +What: /sys/class/net//xdp_linearize > +Date: Jan 2020 > +KernelVersion: 5.6 > +Contact: netdev@vger.kernel.org > +Description: > + boolean controlling whether skb should be linearized in > + generic xdp. Defaults to true. Could you also add a few words explaining what the tradeoff here is? Something like: "turning this off can increase the performance of generic XDP at the cost of making the content of making the XDP program unable to access packet fragments after the first one" -Toke