From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759207AbYIAUJj (ORCPT ); Mon, 1 Sep 2008 16:09:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751568AbYIAUJa (ORCPT ); Mon, 1 Sep 2008 16:09:30 -0400 Received: from www.tglx.de ([62.245.132.106]:44443 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751544AbYIAUJa (ORCPT ); Mon, 1 Sep 2008 16:09:30 -0400 Date: Mon, 1 Sep 2008 22:09:17 +0200 (CEST) From: Thomas Gleixner To: Larry Finger cc: LKML , "Rafael J. Wysocki" , Linus Torvalds , Alok Kataria , Michael Buesch Subject: Re: Regression in 2.6.27 caused by commit bfc0f59 In-Reply-To: <48BC444D.5030601@lwfinger.net> Message-ID: References: <48BB2116.1060904@lwfinger.net> <48BC2A03.9000104@lwfinger.net> <48BC444D.5030601@lwfinger.net> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 1 Sep 2008, Larry Finger wrote: > The timed sleep is as accurate as I can measure. > > I put in some test prints. The value of pm2 is zero when the else branch of > the "if (hpet)" is entered; however, pm1 is 15768471. When we reach the > do_div(tsc2, tsc1) statement, tsc2 is zero, which I think means that the two > calls to tsc_read_refs() are returning the same junk value. Ok, so the pmtimer is probably detected later as unusable and disabled. Please check your logs for: "PM-Timer had inconsistent results:" Thanks, tglx