From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758707AbZFYErd (ORCPT ); Thu, 25 Jun 2009 00:47:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751192AbZFYErZ (ORCPT ); Thu, 25 Jun 2009 00:47:25 -0400 Received: from mail-bw0-f213.google.com ([209.85.218.213]:39830 "EHLO mail-bw0-f213.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751160AbZFYErY (ORCPT ); Thu, 25 Jun 2009 00:47:24 -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=lJMCFd4BpPUUWm1krEQS2tToYa0Qo6anceSMCoU29bl0Jq4PhSFrN3FF6qBKdvpoRC idscNbTYBabTgAWQUDjUHMtyUS43SCUIjuQFPMyKAYgB3fro1WAwA/+93/IRkAt6TNlV 8xOsocO93mkd5gS+AzzIYlqoCS5blK+vpi8Io= Date: Thu, 25 Jun 2009 06:47:23 +0200 From: Frederic Weisbecker To: Li Zefan Cc: Jason Baron , linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, rostedt@goodmis.org, peterz@infradead.org, mathieu.desnoyers@polymtl.ca, jiayingz@google.com, mbligh@google.com, roland@redhat.com, fche@redhat.com Subject: Re: [PATCH 3/7] V2 add syscall tracepoints Message-ID: <20090625044722.GA6071@nowhere> References: <4A42DEF9.4020506@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A42DEF9.4020506@cn.fujitsu.com> 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 25, 2009 at 10:20:41AM +0800, Li Zefan wrote: > > -#define DECLARE_TRACE(name, proto, args) \ > > +#define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg) \ > > extern struct tracepoint __tracepoint_##name; \ > > static inline void trace_##name(proto) \ > > { \ > > @@ -71,13 +73,29 @@ 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; \ > > The explicit cast seems unnecessary. It seems even dangerous. That might hide unmatching callback types passed in macro arguments. Frederic. > > + \ > > + 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_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args), 0, 0); > > I think DECLARE_TRACE_WITH_CALLBACK(..., NULL, NULL) is better. > > > + > > #define DEFINE_TRACE(name) \ > > static const char __tpstrtab_##name[] \ > > __attribute__((section("__tracepoints_strings"))) = #name; \ > > @@ -94,7 +112,7 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin, > > struct tracepoint *end); > > > > #else /* !CONFIG_TRACEPOINTS */ > > -#define DECLARE_TRACE(name, proto, args) \ > > +#define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg) \ > > static inline void _do_trace_##name(struct tracepoint *tp, proto) \ > > { } \ > > static inline void trace_##name(proto) \ > > @@ -108,6 +126,9 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin, > > return -ENOSYS; \ > > } > > > > +#define DECLARE_TRACE(name, proto, args) \ > > + DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args), 0, 0); > > ditto > > > + > > #define DEFINE_TRACE(name) > > #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) > > #define EXPORT_TRACEPOINT_SYMBOL(name) > >