Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755719AbZGGUku (ORCPT ); Tue, 7 Jul 2009 16:40:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752547AbZGGUkl (ORCPT ); Tue, 7 Jul 2009 16:40:41 -0400 Received: from mx2.redhat.com ([66.187.237.31]:46915 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752125AbZGGUkk (ORCPT ); Tue, 7 Jul 2009 16:40:40 -0400 Message-ID: <4A53B338.4060803@redhat.com> Date: Tue, 07 Jul 2009 16:42:32 -0400 From: Masami Hiramatsu User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Frederic Weisbecker CC: Ingo Molnar , Steven Rostedt , lkml , systemtap , kvm , DLE , Ananth N Mavinakayanahalli , Christoph Hellwig , Tom Zanussi Subject: Re: [PATCH -tip -v10 7/7] tracing: add kprobe-based event tracer References: <20090701010838.32547.62843.stgit@localhost.localdomain> <20090701010923.32547.74203.stgit@localhost.localdomain> <20090707073103.GA6173@nowhere> <4A53A830.3000305@redhat.com> <20090707202008.GE6184@nowhere> In-Reply-To: <20090707202008.GE6184@nowhere> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2082 Lines: 66 Frederic Weisbecker wrote: > On Tue, Jul 07, 2009 at 03:55:28PM -0400, Masami Hiramatsu wrote: >> Frederic Weisbecker wrote: >>>> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h >>>> index 206cb7d..65945eb 100644 >>>> --- a/kernel/trace/trace.h >>>> +++ b/kernel/trace/trace.h >>>> @@ -45,6 +45,8 @@ enum trace_type { >>>> TRACE_POWER, >>>> TRACE_BLK, >>>> TRACE_KSYM, >>>> + TRACE_KPROBE, >>>> + TRACE_KRETPROBE, >>>> >>>> __TRACE_LAST_TYPE, >>>> }; >>>> @@ -227,6 +229,22 @@ struct trace_ksym { >>>> char ksym_name[KSYM_NAME_LEN]; >>>> char p_name[TASK_COMM_LEN]; >>>> }; >>>> +#define TRACE_KPROBE_ARGS 6 >>>> + >>>> +struct kprobe_trace_entry { >>>> + struct trace_entry ent; >>>> + unsigned long ip; >>>> + int nargs; >>>> + unsigned long args[TRACE_KPROBE_ARGS]; >>> >>> >>> I see that you actually make use of arg as a dynamic sizeable >>> array. >>> For clarity, args[TRACE_KPROBE_ARGS] could be args[0]. >>> >>> It's just a neat and wouldn't affect the code nor the data >>> but would be clearer for readers of that code. >> Hmm. In that case, I think we'll need a new macro for field >> definition, like TRACE_FIELD_ZERO(type, item). > > > > You mean that for trace_define_field() to describe fields of events? > Actually the fields should be defined dynamically depending on how > is built the kprobe event (which arguments are requested, how many, > etc..). Yeah, if you specified a probe point with its event name, the tracer will make a corresponding event dynamically. There are also anonymous probes which don't have corresponding events. For those anonymous probes, I need to define two generic event types(kprobe and kretprobe). Thank you, -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division e-mail: mhiramat@redhat.com -- 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/