Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754788AbZFFMRz (ORCPT ); Sat, 6 Jun 2009 08:17:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753395AbZFFMRs (ORCPT ); Sat, 6 Jun 2009 08:17:48 -0400 Received: from mx-out2.daemonmail.net ([216.104.160.39]:59978 "EHLO mx-out2.daemonmail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753239AbZFFMRr (ORCPT ); Sat, 6 Jun 2009 08:17:47 -0400 From: "Michael S. Zick" Reply-To: lkml@morethan.org To: Linus Torvalds Subject: Re: Linux 2.6.30-rc8 [also: VIA Support] Date: Sat, 6 Jun 2009 07:17:44 -0500 User-Agent: KMail/1.9.9 Cc: Duane Griffin , Linux Kernel Mailing List , Harald Welte References: <200906041227.10529.lkml@morethan.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200906060717.46964.lkml@morethan.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1855 Lines: 45 On Thu June 4 2009, Linus Torvalds wrote: > > On Thu, 4 Jun 2009, Michael S. Zick wrote: > > > > Yes, I build test cases with and without - - > > It was a fixed-speed kernel build that first hit the 4 hour up-time mark. > > I just reposted that build today (the -09143lk). > > > > > Features like that easily put a huge stress on power regulators etc, if > > > they result in sudden changes in current draw. Underspecced capacitors > > > etc can cause CPU "brown-outs", which in turn can easily cause total > > > failure. > > > > There is also a possible thermal issue with these machines - - > > I doubt that VIA runs their qualification testing in bake ovens; > > which is what NetBook cases amount too. ;) > > If the fixed-speed case runs for longer, it's not likely to be a thermal > issue. The fixed speed case should be the higher-power one. > I can respond to that point now; VIA Tech has answered some of my questions - The mainstream kernel, e_powersaver, is *under-clocking* my machine - The cpuid instruction provides the minimum and maximum GSF values (Guaranteed Stable Frequency) for that processor mask run - Passing that on as the lower and upper limits to e_powersaver should stop that problem. Will be testing this RSN. Once you start operating the processor outside of the reported-by-silicon mask limits - quote: "there is no quarantee of stable operation" - - To that I add my opinion: For a severely under-clocked machine (already possibly un-stable) - - Thermal effects are almost certain to be present. To paraphrase VIA Tech once again: "Don't do that." ;) Mike -- 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/