Re: [PATCH 2/2] selftests: ftrace: Add more verbosity for immediate log

[Masami Hiramatsu <mhiramat@kernel.org>]

On Mon, 3 Jul 2017 09:19:36 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Mon,  3 Jul 2017 14:26:40 +0900
> Masami Hiramatsu <mhiramat@kernel.org> wrote:
> 
> > Add 3-level verbosity for showing traced command log
> > on console immediately. Since some test cases can cause
> > kernel pacic if there is a probrem (like regression etc.),
> > we can not know which command caused the problem without
> > traced command log. This verbosity (-vvv) solves that
> > because it shows the log on console immediately. User
> > can get continuous command/error log.
> > 
> > Note that this is a kind of kernel debug mode, if you
> > don't see any kernel related issue, you don't need this
> > verbosity.
> > 
> > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> > ---
> >  tools/testing/selftests/ftrace/ftracetest |    8 ++++++--
> >  1 file changed, 6 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest
> > index 290cd42..e3f1521 100755
> > --- a/tools/testing/selftests/ftrace/ftracetest
> > +++ b/tools/testing/selftests/ftrace/ftracetest
> > @@ -15,6 +15,7 @@ echo "		-h|--help  Show help message"
> >  echo "		-k|--keep  Keep passed test logs"
> >  echo "		-v|--verbose Increase verbosity of test messages"
> >  echo "		-vv        Alias of -v -v (Show all results in stdout)"
> > +echo "		-vvv       Alias of -v -v -v (Show all commands immediately)"
> >  echo "		-d|--debug Debug mode (trace all shell commands)"
> >  echo "		-l|--logdir <dir> Save logs on the <dir>"
> >  exit $1
> > @@ -56,9 +57,10 @@ parse_opts() { # opts
> >        KEEP_LOG=1
> >        shift 1
> >      ;;
> > -    --verbose|-v|-vv)
> > +    --verbose|-v|-vv|-vvv)
> >        VERBOSE=$((VERBOSE + 1))
> >        [ $1 = '-vv' ] && VERBOSE=$((VERBOSE + 1))
> > +      [ $1 = '-vvv' ] && VERBOSE=$((VERBOSE + 2))
> >        shift 1
> >      ;;
> >      --debug|-d)
> > @@ -252,7 +254,9 @@ run_test() { # testfile
> >    testcase $1
> >    echo "execute$INSTANCE: "$1 > $testlog
> >    SIG_RESULT=0
> > -  if [ $VERBOSE -ge 2 ]; then
> > +  if [ $VERBOSE -ge 3 ]; then
> > +    __run_test $1 | tee -a $testlog 2>&1
> 
> I have nothing against this patch, but I want to point out that the
> above is far from printing everything out immediately. The tee command
> buffers a bit. At least it has for me in the past. If the kernel does
> crash, one needs to still be a bit weary of where exactly the crash
> happened.

Indeed.

> Perhaps we need an option to print not to a log, but just let the test
> print out directly?

OK, then I'd like to add "--logdir -" option instead of this.
(if someone can correct console log, they may not need logfile)

Thank you,

> 
> -- Steve
> 
> 
> 
> > +  elif [ $VERBOSE -eq 2 ]; then
> >      __run_test $1 2>> $testlog | tee -a $testlog
> >    else
> >      __run_test $1 >> $testlog 2>&1
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>