From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754214AbZLARkC (ORCPT ); Tue, 1 Dec 2009 12:40:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754024AbZLARkB (ORCPT ); Tue, 1 Dec 2009 12:40:01 -0500 Received: from ey-out-2122.google.com ([74.125.78.25]:39843 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753840AbZLARkA (ORCPT ); Tue, 1 Dec 2009 12:40:00 -0500 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=iQmAivc+UCYO2GiVem3VREx3tWWo60nmGeI0aM964+2AoanNje5cRMHPu8pM2iLysu KS69GyyePnSc5pHj0QAooivvOFUHTs9J0qhTCGxL41q7B/m18T/VyBaHJraF/33IUeT7 HCr3ojroKjdMDoTXHGu4hz8wJdY462BaE9glk= Date: Tue, 1 Dec 2009 18:40:05 +0100 From: Frederic Weisbecker To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, jbaron@redhat.com, tglx@linutronix.de, laijs@cn.fujitsu.com, mingo@elte.hu Cc: linux-tip-commits@vger.kernel.org Subject: Re: [tip:perf/core] trace_syscalls: Remove unused event_syscall_enter and event_syscall_exit Message-ID: <20091201174002.GA5080@nowhere> References: <4B14D278.4090209@cn.fujitsu.com> 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 Tue, Dec 01, 2009 at 04:42:35PM +0000, tip-bot for Lai Jiangshan wrote: > Commit-ID: bf56a4ea9f1683c5b223fd3a5dbea23f1fa91c34 > Gitweb: http://git.kernel.org/tip/bf56a4ea9f1683c5b223fd3a5dbea23f1fa91c34 > Author: Lai Jiangshan > AuthorDate: Tue, 1 Dec 2009 16:23:20 +0800 > Committer: Ingo Molnar > CommitDate: Tue, 1 Dec 2009 17:33:28 +0100 > > trace_syscalls: Remove unused event_syscall_enter and event_syscall_exit > > fix event_enter_##sname->event > fix event_exit_##sname->event > > remove unused event_syscall_enter and event_syscall_exit > > Signed-off-by: Lai Jiangshan > Acked-by: Jason Baron > Cc: Steven Rostedt > Cc: Frederic Weisbecker > LKML-Reference: <4B14D278.4090209@cn.fujitsu.com> > Signed-off-by: Ingo Molnar > --- I'm confused. Each syscall has a enter_syscall_print_##sname, all of them are identical (they all map to print_syscall_enter()) OTOH we have event_syscall_enter, which is exactly the same than enter_syscall_print_##sname. But we are using a strange mix of them: we do that on init: register_ftrace_event(&enter_syscall_print_##sname) but we use event_syscall_enter as the "event" field of the trace_event. It means that we unregister the wrong event when we remove a module. Thanks for fixing this! But I think you fixed it the wrong way. Why do we need a copy of this event_syscall_enter for each syscall event? Can't we actually drop enter_syscall_print_##sname and always use event_syscall_enter instead? The same applies to exit syscall events. Thanks. > include/linux/syscalls.h | 4 ++-- > include/trace/syscall.h | 2 -- > kernel/trace/trace_syscalls.c | 8 -------- > 3 files changed, 2 insertions(+), 12 deletions(-) > > diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h > index b50974a..2f7c539 100644 > --- a/include/linux/syscalls.h > +++ b/include/linux/syscalls.h > @@ -178,7 +178,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *unused) \ > event_enter_##sname = { \ > .name = "sys_enter"#sname, \ > .system = "syscalls", \ > - .event = &event_syscall_enter, \ > + .event = &enter_syscall_print_##sname, \ > .raw_init = init_enter_##sname, \ > .show_format = syscall_enter_format, \ > .define_fields = syscall_enter_define_fields, \ > @@ -214,7 +214,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *unused) \ > event_exit_##sname = { \ > .name = "sys_exit"#sname, \ > .system = "syscalls", \ > - .event = &event_syscall_exit, \ > + .event = &exit_syscall_print_##sname, \ > .raw_init = init_exit_##sname, \ > .show_format = syscall_exit_format, \ > .define_fields = syscall_exit_define_fields, \ > diff --git a/include/trace/syscall.h b/include/trace/syscall.h > index 51ee17d..5f8827c 100644 > --- a/include/trace/syscall.h > +++ b/include/trace/syscall.h > @@ -37,8 +37,6 @@ extern unsigned long arch_syscall_addr(int nr); > extern int syscall_name_to_nr(char *name); > void set_syscall_enter_id(int num, int id); > void set_syscall_exit_id(int num, int id); > -extern struct trace_event event_syscall_enter; > -extern struct trace_event event_syscall_exit; > > extern int syscall_enter_format(struct ftrace_event_call *call, > struct trace_seq *s); > diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c > index 63aa807..00d6e17 100644 > --- a/kernel/trace/trace_syscalls.c > +++ b/kernel/trace/trace_syscalls.c > @@ -444,14 +444,6 @@ void unreg_event_syscall_exit(struct ftrace_event_call *call) > mutex_unlock(&syscall_trace_lock); > } > > -struct trace_event event_syscall_enter = { > - .trace = print_syscall_enter, > -}; > - > -struct trace_event event_syscall_exit = { > - .trace = print_syscall_exit, > -}; > - > int __init init_ftrace_syscalls(void) > { > struct syscall_metadata *meta;