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=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 E71A8C04AAF for ; Tue, 21 May 2019 11:16:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B942A2081C for ; Tue, 21 May 2019 11:16:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cDYa5bjj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726995AbfEULQZ (ORCPT ); Tue, 21 May 2019 07:16:25 -0400 Received: from mail-yb1-f176.google.com ([209.85.219.176]:34936 "EHLO mail-yb1-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726138AbfEULQZ (ORCPT ); Tue, 21 May 2019 07:16:25 -0400 Received: by mail-yb1-f176.google.com with SMTP id k202so6962533ybk.2; Tue, 21 May 2019 04:16:24 -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=qHKESFWu3uVEowXVX/MvPCRT+aTkRC4ea2S7JZT1F1I=; b=cDYa5bjjEi5TiX7BKmIemQ4LmfzVf2nUsVGq64Kc/mu8g7xa6JqtsS6oDAJ+ZU+HER yDCjQZae2XQqGv/Pw5bvHHmGM3g8e5dTKPNPQiWYpAYaOWVM+SItOzvYjBSsffBDY8sN brOJ/RbEA+HJa/SANyea38MIANy2ZYu2mmPTzpLynR/MbziBvxAme8PkYlKM3bxMA0nm nJxsc5/ak7Uv1x+IRKS3KgH2COieezeVCSCZ1kL3wGXM/2P1gY9nx7BsEErP7DIbBrCE 2raAMhom4F4qpS9UFBf3rsfjDiXCPu2wO3l+4sqfmAVjBKOv3zPHybzfqSKgjPKsn1fN xPHA== 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=qHKESFWu3uVEowXVX/MvPCRT+aTkRC4ea2S7JZT1F1I=; b=oxAn1z8Spizo/mEhqkv4b5q4sQyOdvRpNhir3QndMlKiDlqz+vy1OP82hcXVI7yYdw B4ImL+cqL+9RcgQfNb3IpPVov+9KaYhI2rHRdOKlO6yP8mTpsrN1JsefVCGarJJ2b45s 30BWHSRUslMh2pwW/UXD2bYFoVuiGgOAkiu8x2uLe8FIH4YHQ4EEQUdsjpxCMO34agmf NKUMHy1bcJOr5yld/fn2HPjNCK/OsLdpEG04xzMYzeCu+i2BmjqtGm1NRezV/8jfVG9q hOGkNbDMzmHDKXfBi00q5yAaPRc9tpD6SaR4PdbnD8WqEPIfJpYY3kwKbjwoIWZ3fN/0 mMrg== X-Gm-Message-State: APjAAAUW+R1/D3Exeq2b3y3+1+Sl38a0wTMZYZYa8rqALeHtBgibtblz 1g/yOs3YPprrfMYdSjo8I1coAFePj4quov10eMM= X-Google-Smtp-Source: APXvYqzx693vHzn03Sj+D9wBGIXnVqz/1AaF0r6ryn52oijxf7HsQVy+WYRTWMopirlPQg2lq8f8gGRY2he9l206H/Y= X-Received: by 2002:a25:c6c9:: with SMTP id k192mr3210217ybf.2.1558437383800; Tue, 21 May 2019 04:16:23 -0700 (PDT) MIME-Version: 1.0 References: <9a9ba4c9-3cb7-eb64-4aac-d43b59224442@gmail.com> <20190521104512.2r67fydrgniwqaja@shell.armlinux.org.uk> In-Reply-To: <20190521104512.2r67fydrgniwqaja@shell.armlinux.org.uk> From: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= Date: Tue, 21 May 2019 13:16:12 +0200 Message-ID: Subject: Re: ARM router NAT performance affected by random/unrelated commits To: Russell King - ARM Linux admin Cc: Network Development , linux-arm-kernel , Linux Kernel Mailing List , linux-block@vger.kernel.org, John Crispin , Jonas Gorski , Jo-Philipp Wich , Felix Fietkau Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, 21 May 2019 at 12:45, Russell King - ARM Linux admin wrote: > On Tue, May 21, 2019 at 12:28:48PM +0200, Rafa=C5=82 Mi=C5=82ecki wrote: > > I work on home routers based on Broadcom's Northstar SoCs. Those device= s > > have ARM Cortex-A9 and most of them are dual-core. > > > > As for home routers, my main concern is network performance. That CPU > > isn't powerful enough to handle gigabit traffic so all kind of > > optimizations do matter. I noticed some unexpected changes in NAT > > performance when switching between kernels. > > > > My hardware is BCM47094 SoC (dual core ARM) with integrated network > > controller and external BCM53012 switch. > > Guessing, I'd say it's to do with the placement of code wrt cachelines. That was my guess as well, that's why I tried "cachestat" tool. > You could try aligning some of the cache flushing code to a cache line > and see what effect that has. Can you give me some extra hint on how to do that, please? I tried searching for it a bit but I didn't find any clear article on that matter. --=20 Rafa=C5=82