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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 7BC56CA9EB7 for ; Mon, 21 Oct 2019 13:38:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 528F6214AE for ; Mon, 21 Oct 2019 13:38:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ER4eUBUH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728995AbfJUNiH (ORCPT ); Mon, 21 Oct 2019 09:38:07 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:37026 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728083AbfJUNiG (ORCPT ); Mon, 21 Oct 2019 09:38:06 -0400 Received: by mail-qk1-f193.google.com with SMTP id u184so12620350qkd.4; Mon, 21 Oct 2019 06:38:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=9XSunISr1V5QDmswNDcwodBh42fC8d5U9vuncv4G5IM=; b=ER4eUBUHpUKME3CHPHqs7qIKSq69WImH9o9qDSrUTdhYeMZd5G4iVomPepmt/6kMr3 iLkuFeqKxRlvDxGYgpTs7s4eb03OxSMvygYTzcJvNdoQJB5nJ+3dxDjl+AoN0daJ59FU 6TOFt/9gQ5mrJy6wec4UFSpIb+UYYyS3R2rY5fa/WdczZJZjwmYx0XWE54BafMCm4xUU cB19TRaR/arSPeqPTMJl4KaglfbuFM/LAe9KyWMjYbaxGYiya0UHeROCG3aq1gJPwv0u 5rhZlqzYk9z19NqoJTV6CDTGJJlC+QwGzbiiXtDRio+FVfnlB6hvXwqkwgpDkl7MEWZa /f0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=9XSunISr1V5QDmswNDcwodBh42fC8d5U9vuncv4G5IM=; b=aVHf7/z3eNLuNsARM2BpYfQtJAwKr7Ff7l+d6eTp2xcwtBtUACJAJdz9RCWb2z/AQl EVESp8TUo0NoLdW/gZ+aN35zt485LoRmXD8Va1GMBfQjI7eH61ZDjHGsUSbPlhSjOXCg 1+mCZ/VmhSkKQuLjEHFV47az27R8xhDPWhwvIouB8SC55LlmTmTEQPPOjO8JgSr02WFk BCQA2XvZmru5JCtBNf34Ll+OQ6qU5DktMfKP6FYSE/gRjC/2FmgC1JSNA9YedbTSdhZ/ 1lov1RbWM/rhG/hLi0UJU1XacIqfB+lTlwPuIuqlf+AOWjyKlC4PGkR4h4ZJ51XWu9mS qO8w== X-Gm-Message-State: APjAAAUiGdHtbBNjCuq1B68h6yXU6UlBtkoxqHHY+fbNjpeoNSjYLwGr c5uQEV6FsmxuKk3XX0z/LFdnVVW744SI+Bgd8Eo= X-Google-Smtp-Source: APXvYqzLvDLzIi2FRZYljdcSujCRW8S21SwNQNpJnbMDoz4gADdJu0gIy/GFqrhTRQHH4ZEYFgcf+lujjixoK7gqA2A= X-Received: by 2002:a37:8b03:: with SMTP id n3mr22111950qkd.493.1571665085765; Mon, 21 Oct 2019 06:38:05 -0700 (PDT) MIME-Version: 1.0 References: <20191021105938.11820-1-bjorn.topel@gmail.com> <87h842qpvi.fsf@toke.dk> <87bluaqoim.fsf@toke.dk> In-Reply-To: <87bluaqoim.fsf@toke.dk> From: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= Date: Mon, 21 Oct 2019 15:37:54 +0200 Message-ID: Subject: Re: [PATCH bpf-next v2] libbpf: use implicit XSKMAP lookup from AF_XDP XDP program To: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Cc: Netdev , Alexei Starovoitov , Daniel Borkmann , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , bpf , Magnus Karlsson , "Karlsson, Magnus" , "Samudrala, Sridhar" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, 21 Oct 2019 at 14:19, Toke H=C3=B8iland-J=C3=B8rgensen wrote: > > Bj=C3=B6rn T=C3=B6pel writes: > [...] > > > > bpf_redirect_map() returns a 32-bit signed int, so the upper 32-bit > > will need to be cleared. Having an explicit AND is one instruction > > less than two shifts. So, it's an optimization (every instruction is > > sacred). > > OIC. Well, a comment explaining that might be nice (since you're doing > per-instruction comments anyway)? :) > Sure, I can do a v3 with a comment, unless someone has a better idea avoiding both shifts and AND. Thanks for taking a look! Bj=C3=B6rn > -Toke >