Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758251AbYBYU0u (ORCPT ); Mon, 25 Feb 2008 15:26:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756124AbYBYU0n (ORCPT ); Mon, 25 Feb 2008 15:26:43 -0500 Received: from smtp1.linux-foundation.org ([207.189.120.13]:59018 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754222AbYBYU0m (ORCPT ); Mon, 25 Feb 2008 15:26:42 -0500 Date: Mon, 25 Feb 2008 12:14:40 -0800 From: Andrew Morton To: Gabriel C Cc: Linux Kernel Mailing List , Gabriel C , Thomas Gleixner , john stultz , "Rafael J. Wysocki" Subject: Re: Clocksource tsc is always unstable with 2.6.25-* kernels and CONFIG_NO_HZ=y on my box Message-Id: <20080225121440.32810c91.akpm@linux-foundation.org> In-Reply-To: <47C0BAD9.7030908@googlemail.com> References: <47C0BAD9.7030908@googlemail.com> X-Mailer: Sylpheed 2.4.7 (GTK+ 2.12.1; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1292 Lines: 35 On Sun, 24 Feb 2008 01:31:21 +0100 Gabriel C wrote: > Hi, > > I noticed tsc is always marked unstable on my box with 2.6.25* , 2.6.24 is fine. > > ... > > [ 0.825760] ACPI: PCI Interrupt 0000:03:0e.0[A] -> GSI 22 (level, low) -> IRQ 22 > [ 0.805755] Switched to high resolution mode on CPU 1 > [ 0.794244] Switched to high resolution mode on CPU 2 > [ 0.766968] Switched to high resolution mode on CPU 3 > [ 1.083944] Switched to high resolution mode on CPU 0 > [ 15.388792] Clocksource tsc unstable (delta = 9373391604 ns) > [ 15.714648] Time: acpi_pm clocksource has been installed. > > ... > > Booting nohz=off fixes that. > > Another strange thing is when I try to boot that kernel with clocksource=acpi_pm it just hangs. > > config is attached. > > Please let me know if you need more infos / want me to try patches or anything else. > > I suppose we should consider this a regression. If only because acpi_pm is slower. But mainly because (afaik) this change was not intentional. -- 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/