Re: [PATCH] perf top: fix crash on annotate request

[Brian Gitonga Marete]

On Tue, Dec 6, 2011 at 4:44 PM, Arnaldo Carvalho de Melo
<acme@xxxxxxxxxxxxx> wrote:
>
> Em Tue, Dec 06, 2011 at 10:22:57AM +0300, Brian Gitonga Marete escreveu:
> > On Thu, Dec 1, 2011 at 5:11 PM, Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxx> wrote:
> > > Its just this one, can you try doing something like:
>
> > > perf top -vvv > /tmp/debug.top 2>&1
> > > bzip2 /tmp/debug.top
>
> > > That will print lots of information about symbols being loaded,
> > > overlapping maps, etc that can help me understand why that symbol name
> > > looks garbage.
>
> > > And send me in pvt the result together with a fresh backtrace with those
> > > symbols printed? Also which distro are you using?
>
> > Hello Arnaldo. Curiously, I am unable to reproduce the crash when
> > stdout is redirected to a file. I am able to capture lots of output if
>
> That is good input, so can you please try using just:
>
> perf top --stdio
>
> I.e. probably the problem is with the TUI code and running it in --stdio
> mode will help us pinpoint that. No need to redirect anything.
>

Indeed `--stdio' avoids the crash. See my bisection report below.

> > I redirect stdout to a file in verbose mode, but it won't crash when I
> > do that. Just the same, I am still able to always reproduce (within a
> > few seconds) with your perf/core branch on the tree you pointed me to.
> > This time, I did a `thread apply all bt' in gdb to show the trace for
> > the UI thread since it now seems to me to probably have something with
> > the UI output (because I cannot reproduce if o/put is to a file). The
> > trace is attached in the file gdb.txt.
>
> > Is the `perf top -vvv > /tmp/debug.top 2>&1' output useful even if it
> > is captured in a session that does not crash? If so will send the
> > output privately to you.
>
> please.

Coming in a separate email to you.

> > I am using Ubuntu 10.10
>

Hi. I have bisected this on Linus' tree and the commit that introduced
the crash is: 8b1bfdbdb30

commit 8b1bfdbdb3041c0503c42ef49bab25caabeaa558
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Date:   Wed Oct 5 19:41:31 2011 -0300

perf top: Use the TUI interface by default

It has to do with UI. Reverting it eliminates the crash. (As does
using --stdio as I have said above)

BGM.

--
Brian Gitonga Marete
Toshnix Systems
Tel: +254722151590
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