From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964825AbVHOQZs (ORCPT ); Mon, 15 Aug 2005 12:25:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964821AbVHOQZr (ORCPT ); Mon, 15 Aug 2005 12:25:47 -0400 Received: from e33.co.us.ibm.com ([32.97.110.131]:21652 "EHLO e33.co.us.ibm.com") by vger.kernel.org with ESMTP id S964825AbVHOQZq (ORCPT ); Mon, 15 Aug 2005 12:25:46 -0400 Date: Mon, 15 Aug 2005 21:17:26 +0530 From: Srivatsa Vaddagiri To: Kyle Moffett Cc: Con Kolivas , ck@vds.kolivas.org, Tony Lindgren , tuukka.tikkanen@elektrobit.com, Andrew Morton , johnstul@us.ibm.com, linux-kernel Kernel , Andi Kleen , george@mvista.com Subject: Re: [ck] [PATCH] dynamic-tick patch modified for SMP Message-ID: <20050815154726.GB4731@in.ibm.com> Reply-To: vatsa@in.ibm.com References: <20050812201946.GA5327@in.ibm.com> <200508140053.21056.kernel@kolivas.org> <20050813164618.GA4659@in.ibm.com> <200508141018.29668.kernel@kolivas.org> <6189ECD1-1CE7-4E36-B9F4-FD4D9E5871FA@mac.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6189ECD1-1CE7-4E36-B9F4-FD4D9E5871FA@mac.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Aug 14, 2005 at 12:15:38AM -0400, Kyle Moffett wrote: > It may be a good idea to rebase this patch off the new generic time- > keeping > subsystem that John Stultz is working on. I _am_ using the new subsystem interface (->mark_offset) to catch up with lost ticks. Only I don't think it is that good at catching up the lost ticks if we skip ticks for few seconds in a stretch. For ex: I am observing drift (time slows down) when skipping ticks for upto 5 seconds on a 699MHz P3 SMP hardware. Both TSC and ACPI pm timer give this drift. I am investigating this and will post an update as soon as I get more information. -- Thanks and Regards, Srivatsa Vaddagiri, Linux Technology Center, IBM Software Labs, Bangalore, INDIA - 560017