Message-ID: <1363744741.6345.4.camel@gandalf.local.home>
Subject: Re: [PATCH 7/9] perf util: Get rid of read_or_die() in
 trace-event-read.c
From: Steven Rostedt <rostedt@goodmis.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@kernel.org>,
        Namhyung Kim <namhyung.kim@lge.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Frederic Weisbecker <fweisbec@gmail.com>
Date: Tue, 19 Mar 2013 21:59:01 -0400
In-Reply-To: <87a9pyj227.fsf@sejong.aot.lge.com>
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	 <1363683224-28804-8-git-send-email-namhyung@kernel.org>
	 <1363704867.5938.28.camel@gandalf.local.home>
	 <87a9pyj227.fsf@sejong.aot.lge.com>
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On Wed, 2013-03-20 at 10:24 +0900, Namhyung Kim wrote:

> >> @@ -61,8 +61,10 @@ static int do_read(int fd, void *buf, int size)
> >>  		if (repipe) {
> >>  			int retw = write(STDOUT_FILENO, buf, ret);
> >>  
> >> -			if (retw <= 0 || retw != ret)
> >> -				die("repiping input file");
> >> +			if (retw <= 0 || retw != ret) {
> >> +				pr_debug("repiping input file");
> >
> > Again, why debug and not err?
> 
> Well, there's a pr_err() at the caller of top-level trace_report() in
> case of error.  So if we use pr_err() there'll be multiple error message
> for one failure and I don't think it's so helpful to normal users.  If
> one really wants to know what happens inside, she will set -v to see
> this low-level debug message.
> 
> Does that make sense?
> 

I haven't looked at the context of all the changes as to where they are
called from. I'm fine if we have a methodology of having pr_err() at the
top level and pr_debug() within the nested code. It looked to me that
the choices were somewhat random, but then again, I was missing context
to the code.

As long as a pr_err() that gives the user enough information to know
what went wrong is displayed, I'm fine with other errors using
pr_debug().

-- Steve


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