Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756450AbZKCHdJ (ORCPT ); Tue, 3 Nov 2009 02:33:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756236AbZKCHdI (ORCPT ); Tue, 3 Nov 2009 02:33:08 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:50239 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753467AbZKCHdH (ORCPT ); Tue, 3 Nov 2009 02:33:07 -0500 Date: Tue, 3 Nov 2009 08:32:36 +0100 From: Ingo Molnar To: Masami Hiramatsu Cc: Arnaldo Carvalho de Melo , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , lkml , Steven Rostedt , Jim Keniston , Ananth N Mavinakayanahalli , Christoph Hellwig , "Frank Ch. Eigler" , "H. Peter Anvin" , Jason Baron , "K.Prasad" , Peter Zijlstra , Srikar Dronamraju , systemtap , DLE Subject: Re: [PATCH -tip perf/probes 00/10] x86 insn decoder bugfixes and perf-probe syntax changes Message-ID: <20091103073236.GB19928@elte.hu> References: <20091027204156.30545.96425.stgit@harusame> <20091029085348.GD26970@elte.hu> <4AE9C919.4070003@redhat.com> <4AEF4C29.2060501@redhat.com> <4AEF7B22.50705@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4AEF7B22.50705@redhat.com> User-Agent: Mutt/1.5.19 (2009-01-05) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1347 Lines: 35 * Masami Hiramatsu wrote: > Masami Hiramatsu wrote: >> Masami Hiramatsu wrote: >>> Ingo Molnar wrote: >>>> What we want here is two fold: >>>> >>>> - enable kprobes event support when perf events is enabled and kprobes >>>> is enabled. We dont want another config option for it. >>> >>> Sure, at least that combination should enable kprobe-tracer forcibly. >> >> Hmm, someone may not want to enables kprobe-tracer. Perhaps, >> "default y if (EVENT_PROFILE)" is enough, isn't it? > > Oops, this causes recursive dependency error :-( > > kernel/trace/Kconfig:90:error: found recursive dependency: TRACING -> > EVENT_TRACING -> EVENT_PROFILE -> KPROBE_TRACER -> GENERIC_TRACER -> TRACING This dependency problem can be resolved by simply making it 'default y' - the option itself depends on KPROBES already, which is default-off - so no need to also make it depend on EVENT_PROFILE. btw., it would be nice to re-name it to 'KPROBE_EVENTS'. If the probe point is used as a count - like in the __switch_to example i cited - there's no tracing going on at all. Ingo -- 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/