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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 B8B14C1975A for ; Wed, 25 Mar 2020 14:38:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DAA22077D for ; Wed, 25 Mar 2020 14:38:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rTMOQ5Cw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727799AbgCYOij (ORCPT ); Wed, 25 Mar 2020 10:38:39 -0400 Received: from mail-qk1-f196.google.com ([209.85.222.196]:44033 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727501AbgCYOij (ORCPT ); Wed, 25 Mar 2020 10:38:39 -0400 Received: by mail-qk1-f196.google.com with SMTP id j4so2700940qkc.11 for ; Wed, 25 Mar 2020 07:38:38 -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; bh=U51UPV7zMiOvaN9/pNCFSNDzmUSo2QQcK4hWXxfWQac=; b=rTMOQ5CwamJV7YX5HUqLlBTz+oIM2WCE588UqKx9PtBZkX9QXJl0/cjgbycOSCz/RJ ai1uSmp3lMazoJD/+PKj3GKeTQkUvCHF2BX597V6A+7/eWjvPMPPe/Djn1ABlp5SJdYd LPqAImazbBSQw0gX/rhjgc2eekJzuJu+2X85NK2jhMv+lsDIWP+1Ab7On4OqOFbneHqy 4p9qXpAWOOR4bhkpuxPbB4lQ3ZjuALhJ6vGTaNX6LgwiYLn+5kv3boLt6crRa2U3/f03 A1mltDHvuJFYlzpzY6CLCECvtwPhBfbve9DFgwDD+2a1gmrvFThOpXD/cjClvbQRrO2X J1vw== 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; bh=U51UPV7zMiOvaN9/pNCFSNDzmUSo2QQcK4hWXxfWQac=; b=dxrxcHZE4bVmnKhe8KJ+6vS1Rc5nmQcjJVLdZ0XKJL7pH5Yl2RlPy2zY8KldWyCAOX WHN8Yzqvpxs2OZjtKIY9FlMJnz/1IqH41gj1xLUJAk39wOab42n87RWXTc1BCsscF/Nt 7slR5+HMgQjmTMbwqR3GvWzq9MH+HvalCp07d/WlzJ98MIWzq2ULWFowvuA3HQam/bj3 bzBMQ+b4WtBvSDZgqG9ldgYktlvR8lyrQV7lHCHfSx0gy69qvNLfak9iWljFENkequpN eP9Cxa1qRKsFI1/A/MHj4gYYeAkDNFozZiJcylrz8lXdft6zcq3sJq2yDo8FAPBAAzes ozAg== X-Gm-Message-State: ANhLgQ2WwtN+N8zItD47vL6TVCUtM99I26QakR4VnQjOv2RNrcF9sOU2 iYBauH5lxYxqln2IB179//iK9Tcz X-Google-Smtp-Source: ADFU+vtflNO/m+Goyyg+FTpOySDeyLxqDUsOk5HPq0uFjEG59w6deAGtswxQK84NTich9rjxDSlHYw== X-Received: by 2002:a37:ae04:: with SMTP id x4mr3156672qke.278.1585147117349; Wed, 25 Mar 2020 07:38:37 -0700 (PDT) Received: from mail-yb1-f177.google.com (mail-yb1-f177.google.com. [209.85.219.177]) by smtp.gmail.com with ESMTPSA id j6sm4421030qti.25.2020.03.25.07.38.36 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 25 Mar 2020 07:38:36 -0700 (PDT) Received: by mail-yb1-f177.google.com with SMTP id 11so1248606ybj.11 for ; Wed, 25 Mar 2020 07:38:36 -0700 (PDT) X-Received: by 2002:a25:1042:: with SMTP id 63mr5888502ybq.165.1585147115668; Wed, 25 Mar 2020 07:38:35 -0700 (PDT) MIME-Version: 1.0 References: <20200325140845.11840-1-yang_y_yi@163.com> In-Reply-To: <20200325140845.11840-1-yang_y_yi@163.com> From: Willem de Bruijn Date: Wed, 25 Mar 2020 10:37:59 -0400 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH net-next] net/packet: fix TPACKET_V3 performance issue in case of TSO To: yang_y_yi@163.com Cc: Network Development , u9012063@gmail.com, yangyi01@inspur.com Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Mar 25, 2020 at 10:10 AM wrote: > > From: Yi Yang > > TPACKET_V3 performance is very very bad in case of TSO, it is even > worse than non-TSO case. For Linux kernels which set CONFIG_HZ to > 1000, req.tp_retire_blk_tov = 1 can help improve it a bit, but some > Linux distributions set CONFIG_HZ to 250, so req.tp_retire_blk_tov = 1 > actually means req.tp_retire_blk_tov = 4, it won't have any help. > > This fix patch can fix the aforementioned performance issue, it can > boost the performance from 3.05Gbps to 16.9Gbps, a very huge > improvement. It will retire current block as early as possible in > case of TSO in order that userspace application can consume it > in time. > > Signed-off-by: Yi Yang I'm not convinced that special casing TSO packets is the right solution here. We should consider converting TPACKET_V3 to hrtimer and allow usec resolution block timer. Would that solve your issue?