From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932278AbbFIIPs (ORCPT ); Tue, 9 Jun 2015 04:15:48 -0400 Received: from www.linutronix.de ([62.245.132.108]:45000 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751073AbbFIIP3 (ORCPT ); Tue, 9 Jun 2015 04:15:29 -0400 Date: Tue, 9 Jun 2015 10:15:31 +0200 (CEST) From: Thomas Gleixner To: Andy Lutomirski cc: Len Brown , Andy Lutomirski , X86 ML , Linux PM list , "linux-kernel@vger.kernel.org" , Len Brown Subject: Re: [PATCH 1/1] x86 TSC: set X86_FEATURE_TSC_RELIABLE, per CPUID In-Reply-To: Message-ID: References: <556CA704.1070000@kernel.org> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 8 Jun 2015, Andy Lutomirski wrote: > On Wed, Jun 3, 2015 at 12:03 PM, Len Brown wrote: > > If you boot this machine with "tsc=reliable", to disable the cpu_up > > check_tsc_sync, > > what happens? Does the run-time clocksource code detect the bogus TSC values? > > If yes, how long does that take? > > They didn't detect it in the time I watched it. Which is not surprising as the run-time check is disabled with the reliable flag as well. if (tsc_clocksource_reliable) clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY; Thanks, tglx