From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934169AbaEGNgT (ORCPT ); Wed, 7 May 2014 09:36:19 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:45076 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933281AbaEGNgQ (ORCPT ); Wed, 7 May 2014 09:36:16 -0400 Date: Wed, 7 May 2014 14:35:47 +0100 From: One Thousand Gnomes To: Eric Dumazet Cc: Andi Kleen , josh@joshtriplett.org, David Miller , andi@firstfloor.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, tom.zanussi@linux.intel.com Subject: Re: [PATCH 08/24] net, diet: Make TCP metrics optional Message-ID: <20140507143547.638c6fc2@alan.etchedpixels.co.uk> In-Reply-To: <1399407478.15399.81.camel@edumazet-glaptop2.roam.corp.google.com> References: <1399328773-6531-9-git-send-email-andi@firstfloor.org> <20140505.231229.136734008603421707.davem@davemloft.net> <20140506032114.GP2382@two.firstfloor.org> <20140505.232327.578134514220748085.davem@davemloft.net> <20140506155703.GA20391@cloud> <1399394359.15399.20.camel@edumazet-glaptop2.roam.corp.google.com> <20140506183216.GM19657@tassilo.jf.intel.com> <1399407478.15399.81.camel@edumazet-glaptop2.roam.corp.google.com> Organization: Intel Corporation X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.20; x86_64-pc-linux-gnu) 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 Tue, 06 May 2014 13:17:58 -0700 Eric Dumazet wrote: > On Tue, 2014-05-06 at 11:32 -0700, Andi Kleen wrote: > > > We simply can not compete with user space, as a programmer is free to > > > keep what he really wants/needs. > > > > Not true. > > You can shake the kernel as much as you want, you wont make : > - a TCP socket > - a dentry > - an inode > - a file structure > - eventpoll structures (assuming epoll use) > - 2 dst per flow. > > In 1024 bytes of memory, and keep an efficient kernel to handle > arbitrary number of sockets using the venerable and slow BSD socket api. IoT devices don't care. Most embedded devices don't care. A lot of the current generation of proprietary non Linux very low end RTOS systems support *one socket*, some even use a wireless controller which has a proprietary mini tcp/ip and wifi stack that provices *one socket* If you want Linux to run on the kind of low end 'single chip' systems or FPGA systems then you want to be able to run in very little memory. Network performance is usually near irrelevant. If its controlling a smart plug it doesn't need to do megabit encrypted streams or fast connect. Alan