Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755540AbaAVMIZ (ORCPT ); Wed, 22 Jan 2014 07:08:25 -0500 Received: from merlin.infradead.org ([205.233.59.134]:53477 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753856AbaAVMIX (ORCPT ); Wed, 22 Jan 2014 07:08:23 -0500 Date: Wed, 22 Jan 2014 13:07:57 +0100 From: Peter Zijlstra To: Markus Trippelsdorf 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: <20140122120757.GL31570@twins.programming.kicks-ass.net> References: <20131212140835.729222186@infradead.org> <20131212141655.362219382@infradead.org> <52DEF495.2020304@oracle.com> <20140122104532.GJ31570@twins.programming.kicks-ass.net> <20140122120048.GB389@x4> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140122120048.GB389@x4> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 22, 2014 at 01:00:48PM +0100, Markus Trippelsdorf wrote: > FYI it happens on real hardware on my machine: > ... > [ 0.000000] Hierarchical RCU implementation. > [ 0.000000] NR_IRQS:4352 nr_irqs:712 16 > [ 0.000000] spurious 8259A interrupt: IRQ7. > [ 0.000000] Console: colour VGA+ 80x25 > [ 0.000000] console [tty0] enabled > [ 0.000000] hpet clockevent registered > [ 0.000000] tsc: Fast TSC calibration using PIT > [ 0.003333] tsc: Detected 3210.681 MHz processor > [ 60.375238] Calibrating delay loop (skipped), value calculated using timer frequency.. 6423.91 BogoMIPS (lpj=10702270) > [ 60.375240] pid_max: default: 32768 minimum: 301 > [ 60.375259] Mount-cache hash table entries: 256 > [ 60.375373] tseg: 0000000000 > [ 60.375377] CPU: Physical Processor ID: 0 > [ 60.375377] CPU: Processor Core ID: 0 > [ 60.375378] mce: CPU supports 6 MCE banks > [ 60.375382] LVT offset 0 assigned for vector 0xf9 > [ 60.375384] process: using AMD E400 aware idle routine > [ 60.375386] Last level iTLB entries: 4KB 512, 2MB 16, 4MB 8 Should have always happened like that I think. From the log it looks like the moment we switch from jiffies to actual TSC in arch/x86/kernel/tsc.c:sched_clock(). I don't think I changed the logic there, just switched from a condition to a jump_label. -- 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/