Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755177AbZJTGwY (ORCPT ); Tue, 20 Oct 2009 02:52:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752785AbZJTGwX (ORCPT ); Tue, 20 Oct 2009 02:52:23 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:35757 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750874AbZJTGwX (ORCPT ); Tue, 20 Oct 2009 02:52:23 -0400 Date: Tue, 20 Oct 2009 08:51:51 +0200 From: Ingo Molnar To: Masami Hiramatsu Cc: Frederic Weisbecker , Steven Rostedt , lkml , Thomas Gleixner , Arnaldo Carvalho de Melo , Mike Galbraith , Paul Mackerras , Peter Zijlstra , Christoph Hellwig , Ananth N Mavinakayanahalli , Jim Keniston , "Frank Ch. Eigler" , "H. Peter Anvin" , systemtap , DLE Subject: Re: [PATCH -tip tracing/kprobes 0/9] tracing/kprobes, perf: perf probe and kprobe-tracer bugfixes Message-ID: <20091020065151.GM8550@elte.hu> References: <20091017000711.16556.69935.stgit@dhcp-100-2-132.bos.redhat.com> <20091017080203.GA4155@elte.hu> <20091017103427.GA31238@elte.hu> <4ADAAF50.9040604@redhat.com> <20091019075103.GF17960@elte.hu> <20091019110055.GA5549@nowhere> <20091019112125.GA12829@elte.hu> <4ADCC348.2020800@redhat.com> <4ADCEE1B.40003@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4ADCEE1B.40003@redhat.com> User-Agent: Mutt/1.5.19 (2009-01-05) X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=none autolearn=no SpamAssassin version=3.2.5 _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1809 Lines: 60 * Masami Hiramatsu wrote: > Masami Hiramatsu wrote: > > Ingo Molnar wrote: > >> For example you might want to probe the point within schedule that calls > >> switch_mm() - this could be done via: > >> > >> perf probe schedule@switch_mm > >> > >> Or the point where 'next' gets assigned? Sure, you dont need to even > >> open the editor, if you know the rough outline of the function you can > >> probe it via: > >> > >> perf probe schedule@'next =' > >> > >> Note that i was able to specify both probes without having opened an > >> editor - just based on the general knowledge of the scheduler. > > > > It may be useful for return probe too :-) > > > > perf probe schedule@return > > Hmm, IMHO, > > >> perf probe schedule@switch_mm > > might be confused as 'probe schedule() called from switch_mm()'. > > BTW, there might be several local/inline functions which have > same name. > I think we'd better provide a syntax for solving this issue. > And current syntax uses @ for this purpose as below. > > perf probe localfunc@file > > Maybe, we still can use % for special matching, > > perf probe schedule%switch_mm > > These can be combined with each other, as below. > > perf probe schedule@kernel/sched.c%switch_mm > > Or, supporting lazy string pattern matching > (reusing glob matching in ftrace?) > > perf probe schedule:'switch_mm(*);' > > Just my thought. I'm not attached to any particular form of syntax here (other than it should be simple and obvious) - we can try and see how it works out. 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/