Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755980AbZD1RzH (ORCPT ); Tue, 28 Apr 2009 13:55:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753083AbZD1Ryz (ORCPT ); Tue, 28 Apr 2009 13:54:55 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:53904 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752735AbZD1Ryy (ORCPT ); Tue, 28 Apr 2009 13:54:54 -0400 Date: Tue, 28 Apr 2009 10:50:14 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: david@lang.hm cc: Tejun Heo , Dave Airlie , Ingo Molnar , LKML Subject: Re: kms in defconfig In-Reply-To: Message-ID: References: <21d7e9970904270121s1c58365bqc8933f8a3ffc5f1a@mail.gmail.com> <20090427083935.GA20941@elte.hu> <21d7e9970904270156v54a6483fs20d5b31c97a1d482@mail.gmail.com> <49F65FA2.4010603@kernel.org> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2135 Lines: 49 On Tue, 28 Apr 2009, david@lang.hm wrote: > > the other items that you mention (netfilter, etc) are actually the easier ones > to deal with (you know what you want), and also the place where it's > impossible to detect what's wanted. Very wrong. Especially about the "you know what you want". Quite frankly, those choices can be hard even for kernel developers, never mind normal users. Have you looked at the _hundreds_ of options for various iptables filtering? Do you know which ones you need? [ Ok, so now you can say "give me the non-complex set" and it will pick the normal ones. It will still ask you about others. I had to ask for that option, and when I did, even the main netfilter developers had to say "ok, I'll have to check". The point being - normal mortals have almost no way of knowing which sw features are good, and which are bad. And yes, some of them are really bad. They not only increase compile time, some of them make for horrible performance. You may want to enable some options that increase debug coverage, but can you tell which of them impact kernel performance by a factor of ten on some loads? ] And that's where starting with a "suggested config" can help. And some of the suggestions really are distro-specific, because sometimes different distributions depend on different features. > > So having some kind of (probably inevitably fairly complex) script that > > you could run to get a config would be good. The problem is that the > > script would need to be distributed with the kernel, yet it would often > > also have some nasty distro issues. > > I've seen people talk about creating such tools, but the responses that I've > seen have tended to discourage them. I suspect that they'd generally end up handling the easy cases, and seldom anything more. At which point they're not all that useful. Linus -- 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/