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 3580EC10F14 for ; Tue, 8 Oct 2019 08:48:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0244A205F4 for ; Tue, 8 Oct 2019 08:48:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="aCJ8pSVt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730006AbfJHIsY (ORCPT ); Tue, 8 Oct 2019 04:48:24 -0400 Received: from mail-qt1-f194.google.com ([209.85.160.194]:45586 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729986AbfJHIsY (ORCPT ); Tue, 8 Oct 2019 04:48:24 -0400 Received: by mail-qt1-f194.google.com with SMTP id c21so23972656qtj.12; Tue, 08 Oct 2019 01:48:24 -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=MY4d1ba2zC1BN01TeBYHV60s3GX0/irz8Swh1uPMXP8=; b=aCJ8pSVtQ/U1L8wcP9oHKAbjxpiP8iI8fn1kXix2WytIIRPrEu8v53j3T9naHLdP8Q kHKOMWUJGa+RljS2uB2PX1v4+gvcaE+bNHLCuFC/f+5SxGEj0S8ktoF6ACGn2Ord30f7 SlgrsuV6p3oZZvJIIbTbURYoVVPKBc+tMa/co/759O+nGWw801HwHT4kvpzwzpuWeuyF vebalQ9HJDcKqOakm3esCTS/0aLlP5/6oKC7rFZsvQLOzD//PLdnOcEdENI3JylArZ4p /oWAl8eIMdQ7ccLtkBe369YFHwWLVSZNZXc484m+ftNDYRsKxQJ/oFvFcxmQcmm/+nZD xMWw== 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=MY4d1ba2zC1BN01TeBYHV60s3GX0/irz8Swh1uPMXP8=; b=D6N9beWoOReFmdXLc6fj2h8ukDgGMTz/h/qbNvZyQBVo6nf5faSCnBpU9q+j5T1gWO oS7WYraZg8gn/IgXT8XuTp4dh/XS78ITPczEECVyD192em77tcoAj9TBII7y0luBtHqf 4fJbw+IYmFdvq87kqKmsUBw1/7JRvZULoLplWZa+2ODFUvJ0ZtiLrKoEfjma4PE4gKjk ja1lUdI3Nzijqs96XKyosXDbJA0rcfK15Q6i34IgAOrbnkq9UKqxZBIxlB+EazfMDwTI TiX6ABAzkxCIDJHyXvPIrf+0OOxtCU4YERvrwU99/EutyU7A44aAj3/EAcgqXjsA3Aaw fhYg== X-Gm-Message-State: APjAAAXACFf+3wOflq41Tffyr2yZZo0NKAqYBLaY0K2Qc3O7vuhuMoPb wL4nFQ8HV3qmJ94vrUjIK5IqTKsJm//jFEzX1Uw= X-Google-Smtp-Source: APXvYqyOh6QlIbokS5MEgFiaev+14npMRHwMv+J5TDQiMb2e7DxPxPjQ2ryPNAmkHP6KwX7zfLRFdCSSy6mqY23kmx0= X-Received: by 2002:ac8:3f96:: with SMTP id d22mr35343389qtk.36.1570524503583; Tue, 08 Oct 2019 01:48:23 -0700 (PDT) MIME-Version: 1.0 References: <1570515415-45593-1-git-send-email-sridhar.samudrala@intel.com> <1570515415-45593-3-git-send-email-sridhar.samudrala@intel.com> <875zkzn2pj.fsf@toke.dk> In-Reply-To: From: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= Date: Tue, 8 Oct 2019 10:48:12 +0200 Message-ID: Subject: Re: [PATCH bpf-next 2/4] xsk: allow AF_XDP sockets to receive packets directly from a queue To: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Cc: Sridhar Samudrala , "Karlsson, Magnus" , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Netdev , bpf , intel-wired-lan , maciej.fijalkowski@intel.com, tom.herbert@intel.com 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 Tue, 8 Oct 2019 at 10:47, Bj=C3=B6rn T=C3=B6pel = wrote: > [...] > > The dependent-read-barrier in READ_ONCE? Another branch -- leave that > to the branch-predictor already! ;-) No, you're right, performance > impact here is interesting. I guess the same static_branch could be > used here as well... > ...and I think the READ_ONCE can be omitted. From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?unknown-8bit?q?Bj=C3=B6rn_T=C3=B6pel?= Date: Tue, 8 Oct 2019 10:48:12 +0200 Subject: [Intel-wired-lan] [PATCH bpf-next 2/4] xsk: allow AF_XDP sockets to receive packets directly from a queue In-Reply-To: References: <1570515415-45593-1-git-send-email-sridhar.samudrala@intel.com> <1570515415-45593-3-git-send-email-sridhar.samudrala@intel.com> <875zkzn2pj.fsf@toke.dk> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Tue, 8 Oct 2019 at 10:47, Bj?rn T?pel wrote: > [...] > > The dependent-read-barrier in READ_ONCE? Another branch -- leave that > to the branch-predictor already! ;-) No, you're right, performance > impact here is interesting. I guess the same static_branch could be > used here as well... > ...and I think the READ_ONCE can be omitted.