Re: [PATCH v7 0/2] perf: add support for logging debug messages to file

[Changbin Du]

On Tue, Nov 26, 2019 at 12:19:11PM -0800, Andi Kleen wrote:
> Changbin Du <changbin.du@xxxxxxxxx> writes:
> 
> > When in TUI mode, it is impossible to show all the debug messages to
> > console. This make it hard to debug perf issues using debug messages.
> > This patch adds support for logging debug messages to file to resolve
> > this problem.
> 
> This was already solved in
> 
> commit f78eaef0e0493f6068777a246b9c4d9d5cf2b7aa
> Author: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> Date:   Fri Nov 21 13:38:00 2014 -0800
> 
>     perf tools: Allow to force redirect pr_debug to stderr.
> 
>     When debugging the tui browser I find it useful to redirect the
>     debug
>         log into a file. Currently it's always forced to the message
>     line.
> 
>     Add an option to force it to stderr. Then it can be easily
>     redirected.
>     
> You can do
> 
> perf report --debug stderr 2> file ...
>
Yes, this is a good alternate approach with existing code. I still think
a new option 'file' is not bad. And later maybe we can ouput debug messages
to file only while errors ouput to both.

> -Andi

-- 
Cheers,
Changbin Du