From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756901AbZFSDlF (ORCPT ); Thu, 18 Jun 2009 23:41:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753490AbZFSDkz (ORCPT ); Thu, 18 Jun 2009 23:40:55 -0400 Received: from mail-ew0-f210.google.com ([209.85.219.210]:45928 "EHLO mail-ew0-f210.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752581AbZFSDky (ORCPT ); Thu, 18 Jun 2009 23:40:54 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=Hp8drfU2Vc0KeMtA4tXT3h5/dFNyX6FP7UqKu6G2YxWCTBGEIr5gBjDEO/oK7domvt UAPRlxNS5ZUpsaXEZ2PkPSUD5fDYxzW7QaTnVVfx5iqgZu6yCRJDgA7H56zZRHgg1Loa HkGVCx+HHvUIOCTzEOjwKAJncGGMjgV9YmVPU= Date: Fri, 19 Jun 2009 05:40:53 +0200 From: Frederic Weisbecker To: Steven Rostedt Cc: Jason Baron , linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, peterz@infradead.org, mathieu.desnoyers@polymtl.ca, jiayingz@google.com, bligh@google.com, roland@redhat.com, fche@redhat.com Subject: Re: [PATCH 3/7] add syscall tracepoints Message-ID: <20090619034052.GJ7903@nowhere> References: <0ee4090012cf46f25d8cd8b022746a43b99d5767.1244837725.git.jbaron@redhat.com> <20090619015954.GA7903@nowhere> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 18, 2009 at 11:29:29PM -0400, Steven Rostedt wrote: > > On Fri, 19 Jun 2009, Frederic Weisbecker wrote: > > > On Fri, Jun 12, 2009 at 05:24:49PM -0400, Jason Baron wrote: > > > > > > Introduce a new 'DECLARE_TRACE_REG()' macro, so that tracepoints can associate > > > an external register/unregister function. > > > > > > > > > Signed-off-by: Jason Baron > > > > > > --- > > > include/linux/tracepoint.h | 27 +++++++++++++++++++++++---- > > > 1 files changed, 23 insertions(+), 4 deletions(-) > > > > > > diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h > > > index 14df7e6..9a3660b 100644 > > > --- a/include/linux/tracepoint.h > > > +++ b/include/linux/tracepoint.h > > > @@ -61,7 +61,7 @@ struct tracepoint { > > > * not add unwanted padding between the beginning of the section and the > > > * structure. Force alignment to the same alignment as the section start. > > > */ > > > -#define DECLARE_TRACE(name, proto, args) \ > > > +#define DECLARE_TRACE_REG(name, proto, args, reg, unreg) \ > > > > > > > > May be it deserves a comment? DECLARE_TRACE_REG() as a name is not enough > > obvious on its own :) > > I agree. I was talking with Christoph Hellwig about doing something > similar with TRACE_EVENT, since he needs to do special things when enabled > and disabled (like enable other trace points). > > But anyway, I totally NAK the name. What about something like > DECLARE_TRACE_WITH_CALLBACK() > > Yes, it is a bit more verbose, but it at least tells what it does. Yeah, sounds good. > The first thing that came to my mind when I saw DECLARE_TRACE_REG, was that > this trace point will pass in "regs" to do things like backtraces. Ah, the first thing that came to me was a tracepoint that did something weird with a mysterious registry...and then my imagination got stucked there. Frederic. > -- Steve > > > > > > > > > > extern struct tracepoint __tracepoint_##name; \ > > > static inline void trace_##name(proto) \ > > > { \ > > > @@ -71,13 +71,29 @@ struct tracepoint { > > > } \ > > > static inline int register_trace_##name(void (*probe)(proto)) \ > > > { \ > > > - return tracepoint_probe_register(#name, (void *)probe); \ > > > + int ret; \ > > > + void (*func)(void) = (void (*)(void))reg; \ > > > + \ > > > + ret = tracepoint_probe_register(#name, (void *)probe); \ > > > + if (func && !ret) \ > > > + func(); \ > > > + return ret; \ > > > } \ > > > static inline int unregister_trace_##name(void (*probe)(proto)) \ > > > { \ > > > - return tracepoint_probe_unregister(#name, (void *)probe);\ > > > + int ret; \ > > > + void (*func)(void) = (void (*)(void))unreg; \ > > > + \ > > > + ret = tracepoint_probe_unregister(#name, (void *)probe);\ > > > + if (func && !ret) \ > > > + func(); \ > > > + return ret; \ > > > } > > > > > > + > > > +#define DECLARE_TRACE(name, proto, args) \ > > > + DECLARE_TRACE_REG(name, TP_PROTO(proto), TP_ARGS(args), 0, 0); > > > + > > > #define DEFINE_TRACE(name) \ > > > static const char __tpstrtab_##name[] \ > > > __attribute__((section("__tracepoints_strings"))) = #name; \ > > > @@ -94,7 +110,7 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin, > > > struct tracepoint *end); > > > > > > #else /* !CONFIG_TRACEPOINTS */ > > > -#define DECLARE_TRACE(name, proto, args) \ > > > +#define DECLARE_TRACE_REG(name, proto, args, reg, unreg) \ > > > static inline void _do_trace_##name(struct tracepoint *tp, proto) \ > > > { } \ > > > static inline void trace_##name(proto) \ > > > @@ -108,6 +124,9 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin, > > > return -ENOSYS; \ > > > } > > > > > > +#define DECLARE_TRACE(name, proto, args) \ > > > + DECLARE_TRACE_REG(name, TP_PROTO(proto), TP_ARGS(args), 0, 0); > > > + > > > #define DEFINE_TRACE(name) > > > #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) > > > #define EXPORT_TRACEPOINT_SYMBOL(name) > > > -- > > > 1.6.0.6 > > > > > > >