Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761156AbYA2ECg (ORCPT ); Mon, 28 Jan 2008 23:02:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754034AbYA2EC3 (ORCPT ); Mon, 28 Jan 2008 23:02:29 -0500 Received: from scrub.xs4all.nl ([194.109.195.176]:1216 "EHLO scrub.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753992AbYA2EC2 (ORCPT ); Mon, 28 Jan 2008 23:02:28 -0500 Date: Tue, 29 Jan 2008 05:02:21 +0100 (CET) From: Roman Zippel X-X-Sender: roman@scrub.home To: john stultz cc: lkml , Andrew Morton , Ingo Molnar , Steven Rostedt Subject: Re: [PATCH] correct inconsistent ntp interval/tick_length usage In-Reply-To: <1201573686.6766.13.camel@localhost> Message-ID: References: <1201142334.6383.40.camel@localhost.localdomain> <1201573686.6766.13.camel@localhost> 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 Content-Length: 914 Lines: 24 Hi, On Mon, 28 Jan 2008, john stultz wrote: > Regardless, current_tick_length() really is the base interval we're > using in the error accumulation loop, so it seems the cleanest interface > to use (just to avoid redundancy at least) when establishing the > clocksource's interval length. Or do you not agree? I see, what you need to use in timex.h for !CONFIG_NO_HZ is: #define NTP_INTERVAL_LENGTH ((s64)LATCH * NSEC_PER_SEC) / (s64)CLOCK_TICK_RATE) this calculates the base length of a clock tick in nsec. current_tick_length() would only work during boot. If you switch clocks later, it would include random adjustments specific to the old clock. bye, Roman -- 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/