From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756393AbZE0UdL (ORCPT ); Wed, 27 May 2009 16:33:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756065AbZE0Ucm (ORCPT ); Wed, 27 May 2009 16:32:42 -0400 Received: from www.tglx.de ([62.245.132.106]:50297 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756007AbZE0Uck (ORCPT ); Wed, 27 May 2009 16:32:40 -0400 Date: Wed, 27 May 2009 22:32:28 +0200 (CEST) From: Thomas Gleixner To: john stultz cc: Jon Hunter , "linux-kernel@vger.kernel.org" , Ingo Molnar Subject: Re: [PATCH 1/2] Dynamic Tick: Prevent clocksource wrapping during idle In-Reply-To: <1243455615.7440.17.camel@localhost.localdomain> Message-ID: References: <4A1D52E3.3040204@ti.com> <1243455615.7440.17.camel@localhost.localdomain> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) 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 Wed, 27 May 2009, john stultz wrote: > > Why do you want to recalculate the whole stuff over and over ? > > > > That computation can be done when the clock source is initialized or > > any fundamental change of the clock parameters happens. > > > > Stick that value into the clocksource struct and just read it out. > > Sigh. > > I was hoping to avoid hanging another bit of junk off of the clocksource > struct. Sure, but buying that 8 bytes with Einsteinian insanity is nuts. > But I guess we could compute that value on registration and keep it > around. Changes to mult could effect things, but should be well within > the 6% safety net we give ourselves. That was my thought as well, but even if we have to go to 12% it's way better than doing repeated nonsense on the way to idle. Thanks, tglx