From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966158AbcHEADr (ORCPT ); Thu, 4 Aug 2016 20:03:47 -0400 Received: from mail-pa0-f49.google.com ([209.85.220.49]:32896 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934762AbcHEADk (ORCPT ); Thu, 4 Aug 2016 20:03:40 -0400 Date: Thu, 4 Aug 2016 17:03:32 -0700 From: Stephen Hemminger To: kan.liang@intel.com Cc: davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jeffrey.t.kirsher@intel.com, mingo@redhat.com, peterz@infradead.org, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net, akpm@linux-foundation.org, keescook@chromium.org, viro@zeniv.linux.org.uk, gorcunov@openvz.org, john.stultz@linaro.org, aduyck@mirantis.com, ben@decadent.org.uk, decot@googlers.com, fw@strlen.de, alexander.duyck@gmail.com, daniel@iogearbox.net, tom@herbertland.com, rdunlap@infradead.org, xiyou.wangcong@gmail.com, hannes@stressinduktion.org, jesse.brandeburg@intel.com, andi@firstfloor.org Subject: Re: [RFC V2 PATCH 00/25] Kernel NET policy Message-ID: <20160804170332.4304a907@xeon-e3> In-Reply-To: <1420076354-4861-1-git-send-email-kan.liang@intel.com> References: <1420076354-4861-1-git-send-email-kan.liang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 31 Dec 2014 20:38:49 -0500 kan.liang@intel.com wrote: > 5. Why disable IRQ balance? > A: Disabling IRQ balance is a common way (recommend way for some devices) to > tune network performance. I appreciate that network tuning is hard, most people get it wrong, and nobody agrees on the right answer. So rather than fixing existing tools or writing new userspace tools to do network tuning, you want to hard code one policy manager in kernel with a /proc interface. Why not make a good userspace tool (like powertop). There are also several IRQ balancing programs, but since irqbalance was championed by one vendor others seem to follow like sheep. I agree that this a real concern but the implementation of this leaves much to be desired and discussed. Why can't this be done outside of the kernel.