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=-10.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 DB4C4C433E6 for ; Mon, 31 Aug 2020 21:02:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4D0D20866 for ; Mon, 31 Aug 2020 21:02:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730118AbgHaVCm (ORCPT ); Mon, 31 Aug 2020 17:02:42 -0400 Received: from www62.your-server.de ([213.133.104.62]:46236 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727019AbgHaVCm (ORCPT ); Mon, 31 Aug 2020 17:02:42 -0400 Received: from sslproxy02.your-server.de ([78.47.166.47]) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1kCqwm-0007RC-Sb; Mon, 31 Aug 2020 23:02:36 +0200 Received: from [178.196.57.75] (helo=pc-9.home) by sslproxy02.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kCqwm-0007Bn-NH; Mon, 31 Aug 2020 23:02:36 +0200 Subject: Re: [PATCH bpf-next] samples/bpf: optimize l2fwd performance in xdpsock To: Magnus Karlsson , bjorn.topel@intel.com, ast@kernel.org, netdev@vger.kernel.org, jonathan.lemon@gmail.com Cc: bpf@vger.kernel.org References: <1598619065-1944-1-git-send-email-magnus.karlsson@intel.com> From: Daniel Borkmann Message-ID: Date: Mon, 31 Aug 2020 23:02:33 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <1598619065-1944-1-git-send-email-magnus.karlsson@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.102.4/25916/Mon Aug 31 15:26:49 2020) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 8/28/20 2:51 PM, Magnus Karlsson wrote: > Optimize the throughput performance of the l2fwd sub-app in the > xdpsock sample application by removing a duplicate syscall and > increasing the size of the fill ring. > > The latter needs some further explanation. We recommend that you set > the fill ring size >= HW RX ring size + AF_XDP RX ring size. Make sure > you fill up the fill ring with buffers at regular intervals, and you > will with this setting avoid allocation failures in the driver. These > are usually quite expensive since drivers have not been written to > assume that allocation failures are common. For regular sockets, > kernel allocated memory is used that only runs out in OOM situations > that should be rare. > > These two performance optimizations together lead to a 6% percent > improvement for the l2fwd app on my machine. > > Signed-off-by: Magnus Karlsson Applied, thanks!