Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030386AbWJUJsQ (ORCPT ); Sat, 21 Oct 2006 05:48:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030385AbWJUJsQ (ORCPT ); Sat, 21 Oct 2006 05:48:16 -0400 Received: from www.osadl.org ([213.239.205.134]:49085 "EHLO mail.tglx.de") by vger.kernel.org with ESMTP id S1030386AbWJUJsP (ORCPT ); Sat, 21 Oct 2006 05:48:15 -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 In-Reply-To: <20061020182527.a07666a4.akpm@osdl.org> 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> Content-Type: text/plain Date: Sat, 21 Oct 2006 11:49:07 +0200 Message-Id: <1161424147.5274.400.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: 1893 Lines: 58 On Fri, 2006-10-20 at 18:25 -0700, Andrew Morton wrote: > On Fri, 20 Oct 2006 22:56:51 +0200 > Ingo Molnar wrote: > > > > > * Andrew Morton wrote: > > > > > Oh. I thought the problem was that the timer stops when the CPU is > > > idle. Maybe I misremembered. I'll try `idle=poll'. > > > > hm, wouldnt in that case the box not boot at all? But yeah, idle=poll > > would be nice. > > idle=poll fixes it. The fan gets a bit noisy though ;) So this is one of the boxen where C2 is actually C3 and lapic stops in C3 mode. Probably BIOS magic. What's the output of /proc/acpi/processor/CPU0/power ? > Perhaps a suitable test would be to set up a PIT interrupt, do a hlt, see > if the APIC timer counter has increased appropriately. Yeah, but it has to be done later in the boot process. Looking into this right now. > I got this: > > [ 43.709238] TSC appears to be running slowly. Marking it as unstable > > How come? It also happens with HIGH_RES_TIMERS=n and NO_HZ=n. It only > seems to happen when idle=poll is given. Should happen always as the TSC is driven by the CPU clock and you have CPUFREQ enabled. > > could you also boot with apic=verbose and send us the full bootlog? > > http://userweb.kernel.org/~akpm/apic.txt [ 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. 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/