From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161190AbWFVTF2 (ORCPT ); Thu, 22 Jun 2006 15:05:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161208AbWFVTF2 (ORCPT ); Thu, 22 Jun 2006 15:05:28 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.31.123]:63379 "EHLO atrey.karlin.mff.cuni.cz") by vger.kernel.org with ESMTP id S1161190AbWFVTF1 (ORCPT ); Thu, 22 Jun 2006 15:05:27 -0400 Date: Thu, 22 Jun 2006 19:47:10 +0200 From: Pavel Machek To: Dave Jones , Pavel Machek , "linux-os (Dick Johnson)" , Andreas Mohr , linux-kernel@vger.kernel.org Subject: Re: [RFC/SERIOUS] grilling troubled CPUs for fun and profit? Message-ID: <20060622174710.GC2959@openzaurus.ucw.cz> References: <20060619191543.GA17187@rhlx01.fht-esslingen.de> <20060619202354.GD26759@redhat.com> <20060619222528.GC1648@openzaurus.ucw.cz> <20060619224130.GA17134@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060619224130.GA17134@redhat.com> User-Agent: Mutt/1.3.27i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > > Another anecdote: Upon fan failure, I once had an athlon MP *completely shatter* > > > (as in broke in two pieces) under extreme heat. > > > > > > This _does_ happen. > > > > If it happens to you... you needed a new cpu anyway. Anything non-historical > > *has* thermal protection. > > That's the single dumbest thing I've read today. Sorry to upset you. > newsflash: you don't get to dictate when I (or anyone else) buys new hardware. > Before its accident, that box happily was my home firewall for 3 years, and > its replacement is actually an /older/ box. I didn't "need a new cpu" at all. > Yep, it is bad... broken machines die. And while proposed patches probably will not hurt, I do not think they will help, and I do not think anyone will ever *test* them. > > BTW I doubt those old athlons can be saved by cli; hlt . (Someone willing to try if old > > athlon can run cli; hlt code w/o heatsink?). > > you snipped the important part of my mail. > > "cpu_relax() and friends aren't going to save a box" > > We have two completely different things being discussed in this thread. > > 1. Fan failure, and the possibility to keep running. > IMO, there's nothing we can do here, and nor should we try. Agreed... so you know that proposed patch would probably not prevent your old box from self-destructing? > 2. Situations where we forcibly lock up and spin the CPU in a tight loop, > producing heat. Given there are CPUs that benefit from cpu_relax() > in such places, adding them so that they don't unnecessarily sit there > sucking power until someone gets to the datacenter to investigate > can only be a good thing. Are you sure that cpu_relax actually does somenthing on pre-pentium-4 machines? > > And no, we probably do not want to enter C2 or C3 from doublefault handler. > > I didn't see that being proposed. Good. Pavel -- 64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms