From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765458AbXGZPSH (ORCPT ); Thu, 26 Jul 2007 11:18:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758435AbXGZPRz (ORCPT ); Thu, 26 Jul 2007 11:17:55 -0400 Received: from mx1.redhat.com ([66.187.233.31]:36493 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757965AbXGZPRy (ORCPT ); Thu, 26 Jul 2007 11:17:54 -0400 Message-ID: <46A8BAEC.9070507@redhat.com> Date: Thu, 26 Jul 2007 12:17:00 -0300 From: Arnaldo Carvalho de Melo Organization: Red Hat Inc. User-Agent: Thunderbird 2.0.0.5 (X11/20070719) MIME-Version: 1.0 To: "Frank Ch. Eigler" CC: Mathieu Desnoyers , Ankita Garg , Arjan van de Ven , linux@bohmer.net, LKML , RT-Users , Ingo Molnar Subject: Re: [Question] Hooks for scheduler tracing (CFS) References: <3efb10970707161246se06ab22i32872cfe6fa4f2f6@mail.gmail.com> <1184615557.2698.3.camel@laptopd505.fenrus.org> <20070726072858.GC13061@in.ibm.com> <20070726133138.GA30559@Krystal> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Frank Ch. Eigler wrote: > Mathieu Desnoyers writes: > > >> [...] >> The problem is also in _stp_print_flush, not *only* in relay code: >> void _stp_print_flush (void) >> ... >> spin_lock(&_stp_print_lock); >> ... >> spin_unlock(&_stp_print_lock); >> >> Those will turn into mutexes with -rt. >> > > Indeed, plus systemtap-generated locking code uses rwlocks, > local_irq_save/restore or preempt_disable, in various places. Could > someone point to a place that spells out what would be more > appropriate way of ensuring atomicity while being compatible with -rt? > https://ols2006.108.redhat.com/2007/Reprints/rostedt-Reprint.pdf And his slides too, haven't checked if they are already only at the OLS site. - Arnaldo