From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755244AbZEJA3b (ORCPT ); Sat, 9 May 2009 20:29:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753984AbZEJA3V (ORCPT ); Sat, 9 May 2009 20:29:21 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:52258 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753691AbZEJA3V (ORCPT ); Sat, 9 May 2009 20:29:21 -0400 To: Kay Sievers Cc: linux-kernel , Greg KH , Jan Blunck References: <1241097822.2516.3.camel@poy> From: ebiederm@xmission.com (Eric W. Biederman) Date: Sat, 09 May 2009 17:29:15 -0700 In-Reply-To: (Kay Sievers's message of "Thu\, 7 May 2009 11\:28\:19 +0200") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=67.169.126.145;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 67.169.126.145 X-SA-Exim-Rcpt-To: kay.sievers@vrfy.org, jblunck@suse.de, greg@kroah.com, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Kay Sievers X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% * [score: 0.4937] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 XM_SPF_Neutral SPF-Neutral * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay Subject: Re: [PATCH] driver-core: devtmpfs - driver core maintained /dev tmpfs X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Kay Sievers writes: > On Thu, May 7, 2009 at 10:17, Eric W. Biederman wrote: > >> sysfs is slow. >> udev is slow. > > Everything is "slow" if you want to boot "fast". It's just numbers, > and this is more about simplicity and reliability, with just the side > effect that it's the fastest you can do, when you don't want to lose > current functionality. My primary concern is that you are inventing a new mechanism when the existing mechanism has known issues that could explain the slowdowns. My secondary concern is we have are adding a new mechanism when the existing mechanism has some significant known issues, that are not currently being addressed. Instead the next shiny bobble is being tackled. Finally I am stumped how creating a couple hundred device nodes can be a significant slowdown in booting. It feels like we your patchset adds a line of code for each device node it intends to create. >> Let's bloat the kernel to solve that problem? > > You want to add namespaces for devices to it? I think it is a logical conclusion, and it might potentially be needed. But that is a long ways out. Eric