From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965210AbVHPNUa (ORCPT ); Tue, 16 Aug 2005 09:20:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965213AbVHPNU3 (ORCPT ); Tue, 16 Aug 2005 09:20:29 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:52963 "EHLO e6.ny.us.ibm.com") by vger.kernel.org with ESMTP id S965212AbVHPNU0 (ORCPT ); Tue, 16 Aug 2005 09:20:26 -0400 Date: Tue, 16 Aug 2005 18:49:42 +0530 From: Srivatsa Vaddagiri To: Con Kolivas Cc: tony@atomide.com, tuukka.tikkanen@elektrobit.com, akpm@osdl.org, johnstul@us.ibm.com, linux-kernel@vger.kernel.org, ak@muc.de, george@mvista.com Subject: Re: [ck] [PATCH] dynamic-tick patch modified for SMP Message-ID: <20050816131942.GD8608@in.ibm.com> Reply-To: vatsa@in.ibm.com References: <20050812201946.GA5327@in.ibm.com> <200508141018.29668.kernel@kolivas.org> <20050815153541.GA4731@in.ibm.com> <200508160230.52860.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200508160230.52860.kernel@kolivas.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 16, 2005 at 02:30:51AM +1000, Con Kolivas wrote: > Time definitely was lost the longer the machine was running. I think I found the reason for time drift. Basically cur_timer->mark_offset doesnt expect to be called from non-timer interrupt handler. Hence it drops one jiffy from the lost count. I fixed this in some "crude" fashion and time has not drifted so far or is pretty much close to what it was in pre-smp version. Will find a neat way to fix this and post a patch soon. > You mean disable it at runtime or not compile it in at all? Disabling it at > runtime caused what I described to you as PIT mode (long stalls etc). I think I have recreated this on a machine here. Disabling CONFIG_DYN_TICK_APIC at compile-time didnt seem to make any difference. Will look at this problem next. -- Thanks and Regards, Srivatsa Vaddagiri, Linux Technology Center, IBM Software Labs, Bangalore, INDIA - 560017