Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965011AbVJDWRK (ORCPT ); Tue, 4 Oct 2005 18:17:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965012AbVJDWRK (ORCPT ); Tue, 4 Oct 2005 18:17:10 -0400 Received: from gate.crashing.org ([63.228.1.57]:3253 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S965011AbVJDWRJ (ORCPT ); Tue, 4 Oct 2005 18:17:09 -0400 Subject: Re: clock skew on B/W G3 From: Benjamin Herrenschmidt To: Marc Cc: Rune Torgersen , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org In-Reply-To: <200510040814.07188.marvin24@gmx.de> References: <200510040814.07188.marvin24@gmx.de> Content-Type: text/plain Date: Wed, 05 Oct 2005 08:14:54 +1000 Message-Id: <1128464094.6417.31.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1292 Lines: 32 On Tue, 2005-10-04 at 08:14 +0200, Marc wrote: > Hi, > > given that this option causes problems on non i386 systems, may I propose to > mark CONFIG_HZ as broken on these architectures and/or use a default value of > 1000 ? I guess this issue can't be fixed in a sane way until 2.6.14 is out. The problem is indeed in via_calibrate_decr(). This routine works on HZ/100 so it will not do any good with HZ not beeing a multiple of 100. Can you test this patch ? Index: linux-work/arch/ppc/platforms/pmac_time.c =================================================================== --- linux-work.orig/arch/ppc/platforms/pmac_time.c 2005-09-22 14:06:18.000000000 +1000 +++ linux-work/arch/ppc/platforms/pmac_time.c 2005-10-05 08:14:17.000000000 +1000 @@ -195,7 +195,7 @@ ; dend = get_dec(); - tb_ticks_per_jiffy = (dstart - dend) / (6 * (HZ/100)); + tb_ticks_per_jiffy = (dstart - dend) / ((6 * HZ)/100); tb_to_us = mulhwu_scale_factor(dstart - dend, 60000); printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %u (%u ticks)\n", - 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/