Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161479AbWHDXrh (ORCPT ); Fri, 4 Aug 2006 19:47:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161584AbWHDXrh (ORCPT ); Fri, 4 Aug 2006 19:47:37 -0400 Received: from terminus.zytor.com ([192.83.249.54]:44963 "EHLO terminus.zytor.com") by vger.kernel.org with ESMTP id S1161479AbWHDXrg (ORCPT ); Fri, 4 Aug 2006 19:47:36 -0400 Message-ID: <44D3DC7E.70100@zytor.com> Date: Fri, 04 Aug 2006 16:47:10 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 1.5.0.4 (X11/20060614) MIME-Version: 1.0 To: Dave Jones , "Eric W. Biederman" , vgoyal@in.ibm.com, fastboot@osdl.org, linux-kernel@vger.kernel.org, Horms , Jan Kratochvil , "H. Peter Anvin" , Magnus Damm , Linda Wang Subject: Re: [RFC] ELF Relocatable x86 and x86_64 bzImages References: <20060804225611.GG19244@in.ibm.com> <20060804233815.GG18792@redhat.com> In-Reply-To: <20060804233815.GG18792@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1312 Lines: 33 Dave Jones wrote: > On Fri, Aug 04, 2006 at 05:14:37PM -0600, Eric W. Biederman wrote: > > > I guess the practical question is do people see a real performance benefit > > when loading the kernel at 4MB? > > Linus claimed lmbench saw some huge wins. Others showed that for eg, > a kernel compile took the same amount of time, so take from that what you will.. > > > Possibly the right solution is to do like I did on x86_64 and simply remove > > CONFIG_PHYSICAL_START, and always place the kernel at 4MB, or something like > > that. > > > > The practical question is what to do to keep the complexity from spinning > > out of control. Removing CONFIG_PHYSICAL_START would seriously help with > > that. > > Given the two primary uses of that option right now are a) the aforementioned > perf win and b) building kexec kernels, I doubt anyone would miss it once > we go relocatable ;-) > We DO want the performance gain with a conventional bootloader. The perf win is about the location of the uncompressed kernel, not the compressed kernel. -hpa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/