Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754490AbaAVTJJ (ORCPT ); Wed, 22 Jan 2014 14:09:09 -0500 Received: from ud10.udmedia.de ([194.117.254.50]:36042 "EHLO mail.ud10.udmedia.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752331AbaAVTJH (ORCPT ); Wed, 22 Jan 2014 14:09:07 -0500 Date: Wed, 22 Jan 2014 20:09:05 +0100 From: Markus Trippelsdorf To: Peter Zijlstra Cc: Sasha Levin , Arjan van de Ven , lenb@kernel.org, rjw@rjwysocki.net, Eliezer Tamir , rui.zhang@intel.com, jacob.jun.pan@linux.intel.com, Mike Galbraith , Ingo Molnar , hpa@zytor.com, paulmck@linux.vnet.ibm.com, Thomas Gleixner , John Stultz , Andy Lutomirski , linux-kernel@vger.kernel.org, dyoung@redhat.com Subject: Re: [PATCH 13/15] sched: Use a static_key for sched_clock_stable Message-ID: <20140122190905.GA391@x4> References: <52DEF495.2020304@oracle.com> <20140122104532.GJ31570@twins.programming.kicks-ass.net> <20140122120048.GB389@x4> <20140122120757.GL31570@twins.programming.kicks-ass.net> <20140122122609.GA392@x4> <20140122123022.GN31570@twins.programming.kicks-ass.net> <20140122131456.GA389@x4> <52DFD50E.800@oracle.com> <20140122183538.GA389@x4> <20140122184253.GN30183@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140122184253.GN30183@twins.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014.01.22 at 19:42 +0100, Peter Zijlstra wrote: > On Wed, Jan 22, 2014 at 07:35:38PM +0100, Markus Trippelsdorf wrote: > > > >FYI it happens on real hardware on my machine: > > > >[ 60.375384] process: using AMD E400 aware idle routine > > > But this is a different issue. I've bisected it to: > > > > commit 20d1c86a57762f0a33a78988e3fc8818316badd4 > > Author: Peter Zijlstra > > Date: Fri Nov 29 15:40:29 2013 +0100 > > > > sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs > > > > Reverting the commit "fixes" the issue: > > Hurm.. Turns out the fix is simple: diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index a3acbac2ee72..d90f7a11d573 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1198,8 +1198,8 @@ void __init tsc_init(void) * up if their speed diverges) */ for_each_possible_cpu(cpu) { - cyc2ns_init(cpu); set_cyc2ns_scale(cpu_khz, cpu); + cyc2ns_init(cpu); } if (tsc_disabled > 0) -- Markus -- 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/