Re: [PATCH v3 0/2] perf: add support for logging debug messages to file

From: Changbin Du
Date: Tue Oct 08 2019 - 08:32:15 EST


On Mon, Oct 07, 2019 at 01:26:24PM +0200, Jiri Olsa wrote:
> On Fri, Oct 04, 2019 at 10:39:52AM +0800, Changbin Du wrote:
> > 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.
> >
> > v3:
> > o fix a segfault issue.
>
> heya,
> getting segfault for this:
>
> [jolsa@krava perf]$ ./perf report -vv 2>out
> Segmentation fault (core dumped)
>
This can be fixed by below change. In this case, log_file is NULL.

--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -37,8 +37,10 @@ int veprintf(int level, int var, const char *fmt, va_list args)
if (var >= level) {
if (use_browser >= 1 && !log_file)
ui_helpline__vshow(fmt, args);
- else
+ else if (log_file)
ret = vfprintf(log_file, fmt, args);
+ else
+ ret = vfprintf(stderr, fmt, args);
}

return ret;



> jirka
>
> > v2:
> > o specific all debug options one time.
> >
> > Changbin Du (2):
> > perf: support multiple debug options separated by ','
> > perf: add support for logging debug messages to file
> >
> > tools/perf/Documentation/perf.txt | 15 ++--
> > tools/perf/util/debug.c | 124 +++++++++++++++++++-----------
> > 2 files changed, 90 insertions(+), 49 deletions(-)
> >
> > --
> > 2.20.1
> >

--
Cheers,
Changbin Du