From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752095AbXCQWpd (ORCPT ); Sat, 17 Mar 2007 18:45:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752138AbXCQWpd (ORCPT ); Sat, 17 Mar 2007 18:45:33 -0400 Received: from nf-out-0910.google.com ([64.233.182.185]:4891 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752095AbXCQWpZ (ORCPT ); Sat, 17 Mar 2007 18:45:25 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:from:to:subject:date:user-agent:cc:references:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:message-id; b=nUanre3QA7YdUk8QGiaq2p3w5qY5wIKQFn4EbMjtuGjbilf7IaPNkPGoRiAYy21RfXpM07qXTSbvnvV2OxaeoNOpeb62VgDZsx7/wFrPmNpCcLqp+UUpsd/c1Si0G972HzhIFpcCiYEurDhJsBrCHqjpGBkhNAvw35yhFcCy+lY= From: Maxim To: Len Brown Subject: Re: [BUG] 2.6.21-rc1,2,3 regressions on my system that I found so far Date: Sun, 18 Mar 2007 00:45:18 +0200 User-Agent: KMail/1.9.6 Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Adrian Bunk , Arjan van de Ven References: <200703161230.03712.maximlevitsky@gmail.com> <1174088686.13341.347.camel@localhost.localdomain> <200703162132.53906.lenb@kernel.org> In-Reply-To: <200703162132.53906.lenb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200703180045.18490.maximlevitsky@gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 17 March 2007 03:32:53 Len Brown wrote: > On Friday 16 March 2007 19:44, Thomas Gleixner wrote: > > Maxim, > > > > On Fri, 2007-03-16 at 12:30 +0200, Maxim Levitsky wrote: > > > 3) Sometimes I get this (once in three boots or so) > > > > > > [ 36.217405] ENABLING IO-APIC IRQs > > > [ 36.217587] ..TIMER: vector=0x31 apic1=0 pin1=2 apic2=-1 pin2=-1 > > > [ 36.433917] APIC timer disabled due to verification failure. > > > > > > And NO_HZ is disabled due to that (I get 1000/s timer's interrupts) > > > I haven't investigated that yet. > > > It looks like another new test that my hardware fails to perform... > > > > Yes, this is probably caused by SMM code trying to emulate a PS/2 > > keyboard from a (maybe connected or not) USB keyboard. Unfortunately we > > have no way to disable this BIOS misfeature in the early boot process. > > Arjan, Len ????? > > Nope. By definition, SMM is invisible to the OS -- we don't even > get a bit that said it occurred (though we'd like one -- it would > be really helpful to diagnose issues like this one) > > So go into BIOS SETUP and see if there is a USB Legacy Emulation > feature that you can disable. Sometimes there is not, but disabling > onboard USB altogether may help at least prove the issue is in that area. > > > I built in this test to rule out bogus LAPIC timer calibration values > > which are sometimes off by factor 2-10. > > > > But I also built in a calibration against the PM-Timer, which turned out > > to be quite reliable and I think the additional verification step is > > only necessary for sytems without PM-Timer. > > > > That was a bit over cautious from my side. I send a patch to avoid this > > when PM-Timer is available in a separate mail. > > PM-Timer was invented to work-around the issue that the TSC became unreliable > in the face of power management on laptops. In particular, to be able > to time duration of OS idle where TSC stopped. > > While it is not fine grain, and it is not low-latency, is should > be very reliable. My understanding is that it is implemented as > a simple divider right off the system 14MHz clock -- the signal > which most motherboard clocks are PLL multiplied up from -- > including the 100MHz front-side bus which drives the LAPIC timer. > > But that said, I don't understand why calibrating the LAPIC timer > using the PM-timer is going to be more reliable -- exactly how > and why did the previous calibration scheme fail? > Maybe I could follow the new logic in apic.c if I saw the "apic=debug" > output for this box. > > cheers, > -Len > > > Hi, Yes, usb emulation is enabled, but I need it. I will test without usb emulation, but since it shows only sometimes, I don't know yet whenever usb legacy affects it. Regards, Maxim Levitsky