Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751180AbVKRXiG (ORCPT ); Fri, 18 Nov 2005 18:38:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751181AbVKRXiF (ORCPT ); Fri, 18 Nov 2005 18:38:05 -0500 Received: from smtp3.Stanford.EDU ([171.67.16.138]:2751 "EHLO smtp3.Stanford.EDU") by vger.kernel.org with ESMTP id S1751180AbVKRXiE (ORCPT ); Fri, 18 Nov 2005 18:38:04 -0500 Subject: Re: 2.6.14-rt13 From: Fernando Lopez-Lezcano To: Steven Rostedt Cc: nando@ccrma.Stanford.EDU, Lee Revell , Ingo Molnar , linux-kernel@vger.kernel.org, "Paul E. McKenney" , "K.R. Foley" , Thomas Gleixner , pluto@agmk.net, john cooper , Benedikt Spranger , Daniel Walker , Tom Rini , George Anzinger In-Reply-To: References: <20051115090827.GA20411@elte.hu> <1132336954.20672.11.camel@cmn3.stanford.edu> <1132350882.6874.23.camel@mindpipe> <1132351533.4735.37.camel@cmn3.stanford.edu> <20051118220755.GA3029@elte.hu> <1132352143.6874.31.camel@mindpipe> Content-Type: text/plain Date: Fri, 18 Nov 2005 15:36:58 -0800 Message-Id: <1132357018.4735.51.camel@cmn3.stanford.edu> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1166 Lines: 31 On Fri, 2005-11-18 at 17:25 -0500, Steven Rostedt wrote: > On Fri, 18 Nov 2005, Lee Revell wrote: > > > On Fri, 2005-11-18 at 23:07 +0100, Ingo Molnar wrote: > > > * Fernando Lopez-Lezcano wrote: > > > > > > > Arghhh, at least I take this as a confirmation that the TSCs do drift > > > > and there is no workaround. It currently makes the -rt/Jack > > > > combination not very useful, at least in my tests. > > > > > > > > Is there a way to resync the TSCs? > > > > > > no reasonable way. Does idle=poll make any difference? > > > > But JACK itself uses rdtsc() for timing calculations so TSC drift is > > invariably fatal. > > Can it simply be pinned to a cpu? Is there a way to know in which cpu a process is running? At least Jack could ignore timinig issues if the measurement is going to happen in a different cpu than the one where the original timestamp was collected. -- Fernando - 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/