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Date: Fri, 6 Jul 2012 14:46:36 -0300
From: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
To: David Ahern <dsahern@gmail.com>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH] perf lock: fix segfault with info subcommand following
 move to libtraceevent
Message-ID: <20120706174636.GC24429@infradead.org>
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Em Fri, Jul 06, 2012 at 11:17:41AM -0600, David Ahern escreveu:
> On 7/6/12 11:14 AM, Arnaldo Carvalho de Melo wrote:
> >Em Fri, Jul 06, 2012 at 10:02:18AM -0600, David Ahern escreveu:
> >>+++ b/tools/perf/builtin-lock.c
> >>@@ -877,6 +877,9 @@ static int read_events(void)
> >>  	if (!session)
> >>  		die("Initializing perf session failed\n");
> >>
> >>+	if (!perf_session__has_traces(session, "lock record"))
> >>+		exit(1);
> >>+
> >>  	return perf_session__process_events(session, &eops);
> >>  }
> >
> >This is getting out of hand, first a die(), then an exit(1) and finally
> >this function returns a value, ouch.
> >
> >I'd rather use return to signal that something went wrong and as well
> >print some helpful warning to the user.
> >
> >Eventually we should fix all the other offenders, but lets try not to
> >add even more.
> 
> Agree. But....
> 
> >
> >Can you please resend with a pr_warning + return failure?
> 
> 
> This command needs some love. The rc is not checked and requires
> some rework. e.g., the report path:
> 
>     setup_pager();
>     select_key();
>     read_events();    <---- the function I changed
>     sort_result();
>     print_result();
> 
> and the info path:
>         setup_pager();
>         read_events();
>         dump_info();
> 
> I figured for 3.5 at least not segfault; clean up for 3.6 or later.

Fair enough, so answering that other question, you want this for
perf/urgent.

Ok, queing it up for that branch,

- Arnaldo