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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 94F10C3F2C6 for ; Tue, 3 Mar 2020 12:12:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6730920857 for ; Tue, 3 Mar 2020 12:12:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gKuJMHAg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729120AbgCCMMQ (ORCPT ); Tue, 3 Mar 2020 07:12:16 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:30463 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727879AbgCCMMP (ORCPT ); Tue, 3 Mar 2020 07:12:15 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583237534; 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=kYcPsyPcZMo0qKyDJhxGZKc3OI/Y2/sXGHZo2fLvyT8=; b=gKuJMHAgMRhr0e4ZZlYTnPBYslSDR4vJA0mVGk8xGGxQsvNE/qeD5LQChtvCTrf4D2EzUJ 0UhVXndk7uwGKUc0p3zsozk339JZdla2NJcZOpOEHPUzq58756Nhk/65X4G2OrraN9rYvH sx2UBQxg34bbUfEhX/Pxk/gKfnEkqEo= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-156-FH9o99OaOmusg8JjM0pYjQ-1; Tue, 03 Mar 2020 07:12:13 -0500 X-MC-Unique: FH9o99OaOmusg8JjM0pYjQ-1 Received: by mail-wr1-f69.google.com with SMTP id y28so1110915wrd.23 for ; Tue, 03 Mar 2020 04:12:12 -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=kYcPsyPcZMo0qKyDJhxGZKc3OI/Y2/sXGHZo2fLvyT8=; b=EJWiqB8f5VyPWZq6vYbkhsb/ifhDpV7F9X4NSAI4wwZS9yOFVubWq/TaWPL2dr/edh 87UjvONwFU8qsTfSwNXC1DlXMlAImzC/rlkxrcFZelEQxHu92n5T/WVqvItoYwnv7Sm9 vLtxGbvyE9zctT+v9KL32Kw8Pc2FzWu8Wn4OZ3LbILukHso6Kbf0Qy1j+C8+0Ry7UGo2 wnFqPH1VlEAE7R8GpEZ8W8XBcWrbnCNzpE1/I2qrKZOpQTi14tsXyB/ohqRv7/Kz12cg go0bAyPVxE/CAhoS34cNTgUjGbHju0tn4GMzRTk1jbdj80ekeKWS2ydQut9GmCl7z9lP IJOQ== X-Gm-Message-State: ANhLgQ2OQPBfjTKmZCX0kRqfJLkXu7Krnunr0KNMcz0SlKdtmH36vV3A Xk9g8tz9USKsWViWY584tft36xSwQNaLiUlwGQ3A4fLB3Y8DvYkmz0IeHZFyR0o1NmrVS/dtvy3 MvVLtPAV6/Bmz X-Received: by 2002:a05:6000:104f:: with SMTP id c15mr5005558wrx.376.1583237531724; Tue, 03 Mar 2020 04:12:11 -0800 (PST) X-Google-Smtp-Source: ADFU+vtpPtU/qVowg+VqUFfk2WR/wwv6QMRuEhkfSrHXArJGcJl769Kez2QBsIHXDfNM92HkZvAkrQ== X-Received: by 2002:a05:6000:104f:: with SMTP id c15mr5005538wrx.376.1583237531531; Tue, 03 Mar 2020 04:12:11 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id o26sm3501111wmc.33.2020.03.03.04.12.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Mar 2020 04:12:10 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 8979F180331; Tue, 3 Mar 2020 13:12:09 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Jesper Dangaard Brouer , bpf@vger.kernel.org Cc: Jesper Dangaard Brouer , gamemann@gflclan.com, lrizzo@google.com, netdev@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Alexander Duyck , Ilias Apalodimas Subject: Re: [bpf-next PATCH] xdp: accept that XDP headroom isn't always equal XDP_PACKET_HEADROOM In-Reply-To: <158323601793.2048441.8715862429080864020.stgit@firesoul> References: <158323601793.2048441.8715862429080864020.stgit@firesoul> X-Clacks-Overhead: GNU Terry Pratchett Date: Tue, 03 Mar 2020 13:12:09 +0100 Message-ID: <874kv563ja.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Jesper Dangaard Brouer writes: > The Intel based drivers (ixgbe + i40e) have implemented XDP with > headroom 192 bytes and not the recommended 256 bytes defined by > XDP_PACKET_HEADROOM. For generic-XDP, accept that this headroom > is also a valid size. > > Still for generic-XDP if headroom is less, still expand headroom to > XDP_PACKET_HEADROOM as this is the default in most XDP drivers. > > Tested on ixgbe with xdp_rxq_info --skb-mode and --action XDP_DROP: > - Before: 4,816,430 pps > - After : 7,749,678 pps > (Note that ixgbe in native mode XDP_DROP 14,704,539 pps) > > Signed-off-by: Jesper Dangaard Brouer > --- > include/uapi/linux/bpf.h | 1 + > net/core/dev.c | 4 ++-- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 906e9f2752db..14dc4f9fb3c8 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -3312,6 +3312,7 @@ struct bpf_xdp_sock { > }; > > #define XDP_PACKET_HEADROOM 256 > +#define XDP_PACKET_HEADROOM_MIN 192 Do we need a comment here explaining why there are two values? -Toke