From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754396Ab0EGUiE (ORCPT ); Fri, 7 May 2010 16:38:04 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39930 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751841Ab0EGUiB (ORCPT ); Fri, 7 May 2010 16:38:01 -0400 Message-ID: <4BE479EA.3080005@zytor.com> Date: Fri, 07 May 2010 13:36:58 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: Arjan van de Ven CC: Jacob Pan , Thomas Gleixner , Ingo Molnar , Alek Du , Feng Tang , LKML , Jacob Pan , Linus Torvalds , Arjan van de Ven Subject: Re: RFD: Should we remove the HLT check? (was Re: [PATCH 1/8] x86: avoid check hlt if no timer interrupts) References: <1273254108-3234-1-git-send-email-jacob.jun.pan@linux.intel.com> <1273254108-3234-2-git-send-email-jacob.jun.pan@linux.intel.com> <4BE478C1.2060602@zytor.com> <4BE4791B.1060304@linux.intel.com> In-Reply-To: <4BE4791B.1060304@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/07/2010 01:33 PM, Arjan van de Ven wrote: > On 5/7/2010 13:32, H. Peter Anvin wrote: >> >> I really wish I knew the exact systems affected by the HLT bug. If I >> remember correctly, it was some 386 systems -- or possibly 486 systems >> as well -- a very long time ago. This test just provides a diagnosis if >> the system really is bad (it hangs with an obvious message) at the cost >> of some 40 ms to the system boot time. I suspect C1 (HLT) being broken >> is not anywhere close to the predominant power management problem in the >> current day, and as such I'm wondering if this particular test hasn't >> outlived its usefulness. >> >> Thoughts? > > we could at least hide it behind the "don't run on pentium or newer" config options.. I'd be cool skipping it for family 5 or newer. I'm just wondering if we should kill it completely -- IIRC it was only a handful of 386/486 systems which had problems, usually due to marginal power supplies which couldn't handle the noise of a variable load (DOS not having any power management would run at a reliable 100% load) -- that's not exactly the type of systems which would have survived to modern day. -hpa