Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753225AbeADVaF convert rfc822-to-8bit (ORCPT + 1 other); Thu, 4 Jan 2018 16:30:05 -0500 Received: from smtp-16.smcloud.com ([198.36.167.16]:17327 "HELO smtp-16.smcloud.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752344AbeADVaE (ORCPT ); Thu, 4 Jan 2018 16:30:04 -0500 From: "Tim Mouraveiko" Organization: IPCopper, Inc. To: Andy Shevchenko Date: Thu, 04 Jan 2018 13:31:53 -0800 MIME-Version: 1.0 Subject: Re: Bricked x86 CPU with software? CC: Pavel Machek , Linux Kernel Mailing List Message-ID: <5A4E9D49.11571.23941BD@tim.ml.ipcopper.com> In-reply-to: References: <5A4D7986.2138.FDC590CF@tim.ml.ipcopper.com>, <5A4E9603.20778.21CD7C4@tim.ml.ipcopper.com>, X-mailer: Pegasus Mail for Windows (4.52) Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-description: Mail message body Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: > On Thu, Jan 4, 2018 at 11:00 PM, Tim Mouraveiko wrote: > > Pavel, > > > > As I mentioned before, I repeatedly and fully power-cycled the motherboard and reset BIOS > > and etc. It made no difference. I can see that the processor was not drawing any power. The > > software code behaved in a similar fashion on other processors, until I fixed it so that it would > > not kill any more processors. > > > > In case you are curious there was no overheating, no 100% utilization, no tampering with > > hardware (GPIO pins or anything of that sort), no overclocking and etc. No hardware issues > > or changes at all. > > Please, do not top post. > > Just to be sure, have you checked same CPU on different motherboard? > It might be that voltage regulators on it just died. I did not check the same CPU on a different motherboard, but I did test the code on both the same type of CPU and a different type of CPU. > > > >> > In all my years of extensive experience writing drivers and kernels, I never came across a situation > >> > where you could brick an x86 CPU. Not until recently, when I was working on debugging a piece of > >> > code and I bricked an Intel CPU. I am not talking about an experimental motherboard or anything > >> > exotic or an electrical issue where the CPU got fried, but before the software code execution the CPU > >> > was fine and then it dead. There were signs that something was not right, that the code was causing > >> > unusual behavior, which is what I was debugging. > >> > > >> > Has anyone else ever experienced a bricked CPU after executing software code? I just wanted to get > >> > input from the community to see if anyone had had any experience like that, since it seems rather > >> > unusual to me. > >> > >> Never seen that before. Can you try to brick another one? :-). > >> > >> You may want to remove AC power and battery, wait for half an hour, > >> then attempt to boot it... > >> > >> Pavel > >> -- > >> (english) http://www.livejournal.com/~pavelmachek > >> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html > >> > > > > > > > > -- > With Best Regards, > Andy Shevchenko