From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757237Ab3GLHV7 (ORCPT ); Fri, 12 Jul 2013 03:21:59 -0400 Received: from intranet.asianux.com ([58.214.24.6]:64777 "EHLO intranet.asianux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757132Ab3GLHV6 (ORCPT ); Fri, 12 Jul 2013 03:21:58 -0400 X-Spam-Score: -100.8 Message-ID: <51DFAE5A.2060005@asianux.com> Date: Fri, 12 Jul 2013 15:20:58 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Steven Rostedt CC: Frederic Weisbecker , "mingo@redhat.com" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] kernel: trace: remove __init from race_selftest_startup_function() and trace_selftest_startup_function_graph() References: <51DDFCF8.2090808@asianux.com> <1373561279.17876.45.camel@gandalf.local.home> <51DF44FA.9060000@asianux.com> <1373593261.17876.61.camel@gandalf.local.home> <51DF62DB.3010409@asianux.com> <1373596735.17876.84.camel@gandalf.local.home> <51DF7250.9020209@asianux.com> In-Reply-To: <51DF7250.9020209@asianux.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/12/2013 11:04 AM, Chen Gang wrote: > On 07/12/2013 10:38 AM, Steven Rostedt wrote: >> On Fri, 2013-07-12 at 09:58 +0800, Chen Gang wrote: >>> On 07/12/2013 09:41 AM, Steven Rostedt wrote: >>>> On Fri, 2013-07-12 at 07:51 +0800, Chen Gang wrote: >>>> >>>>>> Hmm, can all trace_selftest_startup_* (*selftest* in trace_selftest.c) >>>>>> use '__init', so not waste memory keeping them around ? >>>> Yeah, they should all be set to __init, but that's pretty low on the >>>> totem poll, as distros don't enable selftests in their main kernels. >>> >>> Excuse me, my English is not quite well, I guess your meaning is: >>> >>> they should all be set to '__init', although it is minor in real world. >>> >>> Is it correct ? >> >> Correct. >> >>> >>> >>> For me, I recommend to let all *selftest* as the same: "all add ' >>> __init' or none add '__init'" (if choose add, all report warnings). >>> >>> Is it suitable to still send new related patch for it ? If so, could >>> you provide your suggesting choice (all add, or none add) ? >> >> Does this patch fix your warning? >> >> -- Steve >> > After the test, they will not report the related warning. Hmm..., but that will let another none *selftest* functions miss '__read_mostly'. Do the original *selftest* intend to have no '__init' so can fit other none *selftest* with '__read_mostly', and without warnings ? Welcome any members' suggestions or completions. Thanks. > I guess it can (although I do not give a compiling test), it seems a > better fixing. > > And is it suitable to let all *selftest* as the same ? (all add, or none > add '__init'). > > Thanks. > >> diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h >> index a4ed382..5e794d1 100644 >> --- a/kernel/trace/trace.h >> +++ b/kernel/trace/trace.h >> @@ -680,6 +680,15 @@ extern int trace_selftest_startup_sched_switch(struct tracer *trace, >> struct trace_array *tr); >> extern int trace_selftest_startup_branch(struct tracer *trace, >> struct trace_array *tr); >> +/* >> + * Tracer data references selftest functions that only occur >> + * on boot up. These can be __init functions. Thus, when selftests >> + * are enabled, then the tracers need to reference __init functions. >> + */ >> +#define __tracer_data __refdata >> +#else >> +/* Tracers are seldom changed. Optimize when selftests are disabled. */ >> +#define __tracer_data __read_mostly >> #endif /* CONFIG_FTRACE_STARTUP_TEST */ >> >> extern void *head_page(struct trace_array_cpu *data); >> diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c >> index b863f93..38fe148 100644 >> --- a/kernel/trace/trace_functions.c >> +++ b/kernel/trace/trace_functions.c >> @@ -199,7 +199,7 @@ static int func_set_flag(u32 old_flags, u32 bit, int set) >> return 0; >> } >> >> -static struct tracer function_trace __read_mostly = >> +static struct tracer function_trace __tracer_data = >> { >> .name = "function", >> .init = function_trace_init, >> >> >> >> > > -- Chen Gang