Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964903AbVJUH5j (ORCPT ); Fri, 21 Oct 2005 03:57:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964901AbVJUH5j (ORCPT ); Fri, 21 Oct 2005 03:57:39 -0400 Received: from ms-smtp-01.nyroc.rr.com ([24.24.2.55]:24505 "EHLO ms-smtp-01.nyroc.rr.com") by vger.kernel.org with ESMTP id S964903AbVJUH5j (ORCPT ); Fri, 21 Oct 2005 03:57:39 -0400 Date: Fri, 21 Oct 2005 03:57:20 -0400 (EDT) From: Steven Rostedt X-X-Sender: rostedt@localhost.localdomain To: Thomas Gleixner cc: Ingo Molnar , john stultz , linux-kernel@vger.kernel.org Subject: Re: Ktimer / -rt9 (+custom) monotonic_clock going backwards. In-Reply-To: <1129880977.16447.116.camel@tglx.tec.linutronix.de> Message-ID: References: <20051020073416.GA28581@elte.hu> <20051020080107.GA31342@elte.hu> <20051020085955.GB2903@elte.hu> <1129826750.27168.163.camel@cog.beaverton.ibm.com> <20051020193214.GA21613@elte.hu> <1129880977.16447.116.camel@tglx.tec.linutronix.de> 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: 1315 Lines: 33 On Fri, 21 Oct 2005, Thomas Gleixner wrote: > On Fri, 2005-10-21 at 02:03 -0400, Steven Rostedt wrote: > > On Thu, 20 Oct 2005, Ingo Molnar wrote: > > > With rc4-rt13 and changing cycle_t to u64, my machine ran all night > > without one backward step. Since it use to show up after a couple of > > hours, I would say that this is the fix. > > > > John, Do you want me to take a crack at changing the periodic_hook into > > using the ktimer code? I understand Ingo's kernel much more than you, but > > you definitely understand the timing code better than I. > > Steve, > > I think the hook is too complex to move it into the timer interrupt > context. We still have to reimplement the dynamic priority adjustment of > the ktimer softirq in a clean way. Once this is done, we can move it > over and set a proper priority up for that. > OK, but the u64 cycle_t should stay. Even with the dynamic priority of the softirq, a process with a super high priority that doesn't care about the timing code can still make the periodic_hook delay for a few seconds. -- 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/