Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750703AbWJVVVk (ORCPT ); Sun, 22 Oct 2006 17:21:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750723AbWJVVVk (ORCPT ); Sun, 22 Oct 2006 17:21:40 -0400 Received: from www.osadl.org ([213.239.205.134]:7126 "EHLO mail.tglx.de") by vger.kernel.org with ESMTP id S1750703AbWJVVVj (ORCPT ); Sun, 22 Oct 2006 17:21:39 -0400 Subject: Re: various laptop nagles - any suggestions? (note: 2.6.19-rc2-mm1 but applies to multiple kernels) From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Andrew Morton Cc: Ingo Molnar , teunis , linux-kernel@vger.kernel.org, Dmitry Torokhov , john stultz , Len Brown In-Reply-To: <1161424147.5274.400.camel@localhost.localdomain> References: <4537A25D.6070205@wintersgift.com> <20061019194157.1ed094b9.akpm@osdl.org> <4538F9AD.8000806@wintersgift.com> <20061020110746.0db17489.akpm@osdl.org> <1161368034.5274.278.camel@localhost.localdomain> <20061020112627.04a4035a.akpm@osdl.org> <1161370015.5274.282.camel@localhost.localdomain> <20061020121537.dea13469.akpm@osdl.org> <20061020203731.GA22407@elte.hu> <20061020135450.6794a2bb.akpm@osdl.org> <20061020205651.GA26801@elte.hu> <20061020182527.a07666a4.akpm@osdl.org> <1161424147.5274.400.camel@localhost.localdomain> Content-Type: text/plain Date: Sun, 22 Oct 2006 23:22:39 +0200 Message-Id: <1161552160.22373.17.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1473 Lines: 33 On Sat, 2006-10-21 at 11:49 +0200, Thomas Gleixner wrote: > [ 11.515305] calibrating APIC timer ... > [ 11.618612] ..... tt1-tt2 831283 > [ 11.618614] ..... mult: 35701101 > [ 11.618616] ..... calibration result: 532021 > [ 11.618619] ..... CPU clock speed is 1995.0325 MHz. > [ 11.618622] ..... host bus clock speed is 133.0021 MHz. > > That looks reasonable. It really boils down to the lapic not working > when going idle. This LAPIC business is weird. I found two boxen, where the LAPIC timer calibration is wrong by factor 1.8 and 2.3 on every third/fifth boot. Unsurprisingly one is a VAIO with a CoreDuo inside, which claims to have a 4.6GHz CPU and 390MHz bus speed occasionally. This problem seems to be independent of the "lapic stops on C2" one. I have a patch ready, which should detect both problems, but having acpi_processor as a module is painful, as we might enable the C2 states way after we decided to use the LAPIC timer and switched over to highres/dyntick mode. I need to find a way to back out from highres/dyntick mode gracefully in that case except we can agree to make the acpi_processor bits built-in only or at least make the Kconfig tristate depending on experimental. Len ? tglx - 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/