Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752459AbYAWV6w (ORCPT ); Wed, 23 Jan 2008 16:58:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751061AbYAWV6m (ORCPT ); Wed, 23 Jan 2008 16:58:42 -0500 Received: from ms-smtp-04.nyroc.rr.com ([24.24.2.58]:32821 "EHLO ms-smtp-04.nyroc.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751216AbYAWV6l (ORCPT ); Wed, 23 Jan 2008 16:58:41 -0500 Date: Wed, 23 Jan 2008 16:58:34 -0500 (EST) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Mathieu Desnoyers cc: LKML , Ingo Molnar , Linus Torvalds , Andrew Morton , Peter Zijlstra , Christoph Hellwig , Gregory Haskins , Arnaldo Carvalho de Melo , Thomas Gleixner , Tim Bird , Sam Ravnborg , "Frank Ch. Eigler" , Jan Kiszka , John Stultz , Arjan van de Ven , Steven Rostedt Subject: Re: [PATCH 06/20 -v5] add notrace annotations for NMI routines In-Reply-To: <20080123213139.GB2282@Krystal> Message-ID: References: <20080123160236.969334052@goodmis.org> <20080123160442.063076557@goodmis.org> <20080123213139.GB2282@Krystal> 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: 1124 Lines: 30 On Wed, 23 Jan 2008, Mathieu Desnoyers wrote: > * Steven Rostedt (rostedt@goodmis.org) wrote: > > This annotates NMI functions with notrace. Some tracers may be able > > to live with this, but some cannot. So we turn off NMI tracing. > > > > One solution might be to make a notrace_nmi which would only turn > > off NMI tracing if a trace utility needed it off. > > > Is this still needed with the atomic clocksource read ? This never had to do with the clocksource. The tracer itself isn't atomic against NMIs. hmm, it may actually be. It does a tracer disable for the CPU by an atomic_inc and this would prevent the NMI from causing harm. I'll test without this patch and see what happens when I turn on a high rate of NMIS. I still want to add a bit more notraces around for the simple reason of cleaning up the output and prehaps speeding up the code a bit. -- 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/