From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264411AbTDOJNp (for ); Tue, 15 Apr 2003 05:13:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264414AbTDOJNp (for ); Tue, 15 Apr 2003 05:13:45 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:14579 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S264411AbTDOJNo (for ); Tue, 15 Apr 2003 05:13:44 -0400 Message-ID: <3E9BCFF8.3050703@mvista.com> Date: Tue, 15 Apr 2003 02:25:12 -0700 From: george anzinger User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2) Gecko/20021202 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Russell King CC: Andrew Morton , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] Fix jiffies_to_time[spec | val] and converse to use actual jiffies increment rather than 1/HZ References: <3E9BC49E.7010903@mvista.com> <20030415095528.B32468@flint.arm.linux.org.uk> In-Reply-To: <20030415095528.B32468@flint.arm.linux.org.uk> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Russell King wrote: > On Tue, Apr 15, 2003 at 01:36:46AM -0700, george anzinger wrote: > >>In the current system (2.5.67) time_spec to jiffies, time_val to >>jiffies and the converse (jiffies to time_val and jiffies to >>time_spec) all use 1/HZ as the measure of a jiffie. Because of the >>inability of the PIT to actually generate an accurate 1/HZ interrupt, >>the wall clock is updated with a more accurate value (999848 >>nanoseconds per jiffie for HZ = 1000). > > > There's an increasing amount of 64-bit math appearing here, which gcc > has been historically bad with. Is there any chance that all this > extra complexity can vanish for architectures which do not have this > problem? I suppose that is possible. On the other hand, the only 64-bit things we leave to C are the "+" and shift. > -- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml