Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751773AbVJTGkK (ORCPT ); Thu, 20 Oct 2005 02:40:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751774AbVJTGkK (ORCPT ); Thu, 20 Oct 2005 02:40:10 -0400 Received: from ms-smtp-02.nyroc.rr.com ([24.24.2.56]:18868 "EHLO ms-smtp-02.nyroc.rr.com") by vger.kernel.org with ESMTP id S1751773AbVJTGkJ (ORCPT ); Thu, 20 Oct 2005 02:40:09 -0400 Date: Thu, 20 Oct 2005 02:39:55 -0400 (EDT) From: Steven Rostedt X-X-Sender: rostedt@localhost.localdomain To: Daniel Walker cc: Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: Ktimer / -rt9 (+custom) monotonic_clock going backwards. In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1023 Lines: 32 On Wed, 19 Oct 2005, Daniel Walker wrote: > On Wed, 19 Oct 2005, Steven Rostedt wrote: > > > > > Hi Thomas, > > > > I switched my custom kernel timer to use the ktimers with the prio of -1 > > as you mentioned to me offline. I set up the timer to be monotonic and > > have a requirement that the returned time is always greater or equal to > > the last time returned from do_get_ktime_mono. > > > > Now here's the results that I got between two calls of do_get_ktime_mono > > > > 358.069795728 secs then later 355.981483177. Should this ever happen? > > Are you running NTP ? > Yes, but that shouldn't make a difference. NTP can slow down or speed up the clock, but it should never make it go backwards. Especially for a monotonic clock (as the name suggests). -- Steve - 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/