Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750750AbVKSSgH (ORCPT ); Sat, 19 Nov 2005 13:36:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750753AbVKSSgG (ORCPT ); Sat, 19 Nov 2005 13:36:06 -0500 Received: from mustang.oldcity.dca.net ([216.158.38.3]:58022 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S1750750AbVKSSgF (ORCPT ); Sat, 19 Nov 2005 13:36:05 -0500 Subject: Re: 2.6.14-rt13 From: Lee Revell To: Vojtech Pavlik Cc: George Anzinger , Fernando Lopez-Lezcano , Ingo Molnar , linux-kernel@vger.kernel.org, "Paul E. McKenney" , "K.R. Foley" , Steven Rostedt , Thomas Gleixner , pluto@agmk.net, john cooper , Benedikt Spranger , Daniel Walker , Tom Rini In-Reply-To: <20051119074503.GA12551@midnight.suse.cz> References: <20051115090827.GA20411@elte.hu> <1132336954.20672.11.camel@cmn3.stanford.edu> <1132350882.6874.23.camel@mindpipe> <1132351533.4735.37.camel@cmn3.stanford.edu> <1132351984.6874.29.camel@mindpipe> <20051118223233.GA7794@midnight.suse.cz> <437E8DC8.4070101@mvista.com> <20051119074503.GA12551@midnight.suse.cz> Content-Type: text/plain Date: Sat, 19 Nov 2005 13:27:06 -0500 Message-Id: <1132424827.6874.64.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.4.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1091 Lines: 24 On Sat, 2005-11-19 at 08:45 +0100, Vojtech Pavlik wrote: > On Fri, Nov 18, 2005 at 06:28:24PM -0800, George Anzinger wrote: > > Finding it is another matter. It does not have a fixed address (i.e. > > it differs from machine to machine, but is constant on any given > > machine). The boot code roots it out of an info block put in memory > > by the BIOS. I suppose one could put a printk in the boot code to > > disclose it... > > There is really no reason to do that, since the time to read it (~1200 > ns) is much less than the time to enter the kernel (less than 200 ns), > so gettimeofday() is definitely easier to use and also doesn't overflow. > Thanks very much, you have answered my question. We would prefer gettimeofday() anyway for portability, so if the plan is to make it faster then we can deal with losing the TSC. Lee - 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/