From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754793AbYIWUGf (ORCPT ); Tue, 23 Sep 2008 16:06:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752189AbYIWUG2 (ORCPT ); Tue, 23 Sep 2008 16:06:28 -0400 Received: from mx1.redhat.com ([66.187.233.31]:54053 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752040AbYIWUG1 (ORCPT ); Tue, 23 Sep 2008 16:06:27 -0400 Message-ID: <48D94BA8.9030106@redhat.com> Date: Tue, 23 Sep 2008 16:03:52 -0400 From: Masami Hiramatsu User-Agent: Thunderbird 2.0.0.16 (X11/20080723) MIME-Version: 1.0 To: Thomas Gleixner CC: Linus Torvalds , Mathieu Desnoyers , Martin Bligh , Linux Kernel Mailing List , Steven Rostedt , darren@dvhart.com, "Frank Ch. Eigler" , systemtap-ml Subject: Re: Unified tracing buffer References: <33307c790809191433w246c0283l55a57c196664ce77@mail.gmail.com> <48D7F5E8.3000705@redhat.com> <33307c790809221313s3532d851g7239c212bc72fe71@mail.gmail.com> <48D81B5F.2030702@redhat.com> <33307c790809221616h5e7410f5gc37c262d83722111@mail.gmail.com> <48D832B6.3010409@redhat.com> <33307c790809221712x4fbd9781u958c98d4585e92a9@mail.gmail.com> <48D901FE.5060604@redhat.com> <20080923150410.GA28341@Krystal> <48D90B84.4030905@redhat.com> <48D921B3.2060809@redhat.com> <48D93CAF.8070000@redhat.com> In-Reply-To: X-Enigmail-Version: 0.95.7 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 Thomas Gleixner wrote: > On Tue, 23 Sep 2008, Masami Hiramatsu wrote: >> # cat /sys/devices/system/cpu/cpu0/cpuidle/state3/usage >> 171210 > > C3 stops the TSC. So depending on how many C3 entries you have on the > different cores, your TSCs will drift apart. Some BIOSes do even a > lousy job trying to fixup the TSCs on exit from C3, which makes things > even worse. > >> C1: type[C1] promotion[--] demotion[--] latency[001] usage[00000016] duration[00000000000000000000] >> C2: type[C2] promotion[--] demotion[--] latency[001] usage[00037969] duration[00000000000024288003] >> C3: type[C3] promotion[--] demotion[--] latency[057] usage[00171818] duration[00000000001881257636] >> >> Could these help you? > > Yup, explains your TSC observation. Nothing we can do about. Broken by > system design :( Welcome in the wonderful world of Inhell/BIOS/ACPI ! Thank you for analyzing! :-) Hmm, then could I fix that by fixing my dsdt...? Thanks again, > > Thanks, > > tglx -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division e-mail: mhiramat@redhat.com