From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTP id 97C1B99D for ; Thu, 8 May 2014 16:32:49 +0000 (UTC) Received: from qmta09.emeryville.ca.mail.comcast.net (qmta09.emeryville.ca.mail.comcast.net [76.96.30.96]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 2818A2034C for ; Thu, 8 May 2014 16:32:49 +0000 (UTC) Date: Thu, 8 May 2014 11:24:39 -0500 (CDT) From: Christoph Lameter To: Josh Triplett Message-ID: Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Sarah Sharp , ksummit-discuss@lists.linuxfoundation.org, Greg KH , Julia Lawall , Darren Hart , Dan Carpenter Subject: Re: [Ksummit-discuss] [CORE TOPIC] Kernel tinification: shrinking the kernel and avoiding size regressions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2 May 2014, Josh Triplett wrote: > - An overview of why the kernel's size still matters today ("but don't > we all have tons of memory and storage?") Kernel size matters quite a bit for performance. Processor caches are key to performance and therefore the cache footprint of a function determines the the possible performance. The smaller the functions and the less data they access the faster they will run. Therefore it needs to be possible to reduce the size of the kernel by disabling unwanted functionality (f.e. cgroups). In order for that to happen features need to be as independent as possible and also the user space tools (like systemd) need to be able to handle a kernel with reduced functionality.