Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755234AbaAVTSA (ORCPT ); Wed, 22 Jan 2014 14:18:00 -0500 Received: from mail-oa0-f43.google.com ([209.85.219.43]:53567 "EHLO mail-oa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752720AbaAVTR7 (ORCPT ); Wed, 22 Jan 2014 14:17:59 -0500 MIME-Version: 1.0 In-Reply-To: <20140122184511.GB389@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> <20140122184511.GB389@x4> Date: Wed, 22 Jan 2014 14:17:58 -0500 X-Google-Sender-Auth: pGLVHQaXn1XrG_PS5hkJ_aT10pw Message-ID: Subject: Re: [PATCH 13/15] sched: Use a static_key for sched_clock_stable From: Josh Boyer To: Markus Trippelsdorf Cc: Peter Zijlstra , Sasha Levin , Arjan van de Ven , Len Brown , "Rafael J. Wysocki" , Eliezer Tamir , Zhang Rui , jacob.jun.pan@linux.intel.com, Mike Galbraith , Ingo Molnar , "H. Peter Anvin" , Paul McKenney , Thomas Gleixner , John Stultz , Andy Lutomirski , "Linux-Kernel@Vger. Kernel. Org" , Dave Young Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 22, 2014 at 1:45 PM, Markus Trippelsdorf wrote: > 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.. what kind of AMD machine is that? > > It's an ancient one: > > processor : 0 > vendor_id : AuthenticAMD > cpu family : 16 > model : 4 > model name : AMD Phenom(tm) II X4 955 Processor > stepping : 2 > microcode : 0x10000db > cpu MHz : 800.000 > cache size : 512 KB > physical id : 0 > siblings : 4 > core id : 0 > cpu cores : 4 > apicid : 0 > initial apicid : 0 > fpu : yes > fpu_exception : yes > cpuid level : 5 > wp : yes > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3 > dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit > wdt hw_pstate npt lbrv svm_lock nrip_save > bogomips : 6424.73 > TLB size : 1024 4K pages > clflush size : 64 > cache_alignment : 64 > address sizes : 48 bits physical, 48 bits virtual > power management: ts ttp tm stc 100mhzsteps hwpstate I'm seeing the odd printk timestamp jump going from 0.xxx to 49.xx on an i7-2600 so it isn't just old hardware. [ 0.000000] kmemleak: Kernel memory leak detector disabled [ 0.000000] ODEBUG: 32 of 32 active objects replaced [ 0.000000] hpet clockevent registered [ 0.000000] tsc: Fast TSC calibration using PIT [ 0.001000] tsc: Detected 3392.351 MHz processor [ 49.777360] Calibrating delay loop (skipped), value calculated using timer frequency.. 6784.70 BogoMIPS (lpj=3392351) [ 49.777363] pid_max: default: 32768 minimum: 301 [ 49.777572] Security Framework initialized josh -- 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/