Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756285Ab3FCJ6C (ORCPT ); Mon, 3 Jun 2013 05:58:02 -0400 Received: from mx1.b1-systems.de ([84.200.69.220]:34019 "EHLO mx1.b1-systems.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755562Ab3FCJ6A (ORCPT ); Mon, 3 Jun 2013 05:58:00 -0400 X-Greylist: delayed 638 seconds by postgrey-1.27 at vger.kernel.org; Mon, 03 Jun 2013 05:57:59 EDT Message-ID: <51AC6625.3080000@message-id.invalid.com> Date: Mon, 03 Jun 2013 11:47:17 +0200 From: Stefan Seyfried User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Frederic Weisbecker CC: LKML , Steven Rostedt , "Paul E. McKenney" , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Borislav Petkov , Li Zhong , Mike Galbraith Subject: Re: [PATCH 2/8] vtime: Use consistent clocks among nohz accounting References: <1369065716-22801-1-git-send-email-fweisbec@gmail.com> <1369065716-22801-3-git-send-email-fweisbec@gmail.com> In-Reply-To: <1369065716-22801-3-git-send-email-fweisbec@gmail.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1669 Lines: 48 Am 20.05.2013 18:01, schrieb Frederic Weisbecker: > While computing the cputime delta of dynticks CPUs, > we are mixing up clocks of differents natures: [...] > As a consequence, some strange behaviour with unstable tsc > has been observed such as non progressing constant zero cputime. > (The 'top' command showing no load). This happens for example on my trusty ThinkPad X200s (family 6 model 23 stepping 10 Core 2 duo), seriously confusing its user (me :-). > Fix this by only using local_clock(), or its irq safe/remote > equivalent, in vtime code. > > Reported-by: Mike Galbraith > Suggested-by: Mike Galbraith > Cc: Steven Rostedt > Cc: Paul E. McKenney > Cc: Ingo Molnar > Cc: Thomas Gleixner > Cc: Peter Zijlstra > Cc: Borislav Petkov > Cc: Li Zhong > Cc: Mike Galbraith > Signed-off-by: Frederic Weisbecker FWIW: Tested-by: Stefan Seyfried This patch fixes the 0% CPU issue on openSUSE Factory kernels for me. Best regards, Stefan -- Stefan Seyfried Linux Consultant & Developer -- GPG Key: 0x731B665B B1 Systems GmbH Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537 -- 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/