Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 19 Feb 2002 15:23:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 19 Feb 2002 15:21:45 -0500 Received: from smtp4.vol.cz ([195.250.128.43]:56330 "EHLO majordomo.vol.cz") by vger.kernel.org with ESMTP id ; Tue, 19 Feb 2002 15:21:30 -0500 Date: Tue, 19 Feb 2002 09:25:03 +0000 From: Pavel Machek To: Tyson D Sawyer Cc: linux-kernel@vger.kernel.org Subject: Re: Missed jiffies Message-ID: <20020219092502.A37@toy.ucw.cz> In-Reply-To: <3C6E77DE.70FE49DF@rwii.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: <3C6E77DE.70FE49DF@rwii.com>; from tyson@rwii.com on Sat, Feb 16, 2002 at 10:16:46AM -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > My system looses about 8 seconds every 20 minutes. This is reported > by ntp and verified by comparing 'date' to 'hwclock --show' and a wall > clock. > > My system is a x86 Dell laptop with HZ=1024. ... > Since I have defined HZ to be 1024, I miss lots of timer interrupts. > However, since the the processor spends 18ms at a time in SMM (System > Mangement Mode), then even the stock 10ms timer tick will sometimes > miss a tick. Thus the problem applies to non-hacked kernels also. Kernel cancompensate for one lost tick, AFAIR, so go back to HZ=100. Pavel -- Philips Velo 1: 1"x4"x8", 300gram, 60, 12MB, 40bogomips, linux, mutt, details at http://atrey.karlin.mff.cuni.cz/~pavel/velo/index.html. - 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/