Re: [PATCH 2/2] tracing/selftests: Add reading all instance files to instance test

[Masami Hiramatsu (Google)]

On Thu, 29 Oct 2026 16:28:51 -0400, Steven Rostedt <rostedt@xxxxxxxxxx> wrote:
> From: Steven Rostedt <rostedt@xxxxxxxxxxx>
> 
> Commit f4a771cc684c7 ("tracing: Have show_event_filters/triggers files take
> trace array ref") fixed a bug where the show_event_filters and triggers
> did not take a trace array reference allowing an instance to be removed
> while active. This would have the reader of these files read data that was
> freed by the remove.
> 
> Update the instance test to read all the files in the instance,
> instance/events, instance/events/sched and
> instance/events/sched/sched_switch directories (with the exception of not
> reading trace or trace_pipe). This would hopefully catch issues with files
> not taking references.
> 
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

Looks good to me.

Reviewed-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Thanks,


> ---
>  .../ftrace/test.d/instances/instance-event.tc | 20 ++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc b/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc
> index b0e9d3abbf2f..9374c20c6aaa 100644
> --- a/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc
> +++ b/tools/testing/selftests/ftrace/test.d/instances/instance-event.tc
> @@ -44,6 +44,19 @@ instance_set() {
>          done 2> /dev/null
>  }
>  
> +instance_cat() {
> +        while :; do
> +		find instances/foo -maxdepth 1 -type f  ! \( -name trace -o -name trace_pipe \) -exec head {} \;
> +		sleep 0.1
> +		find instances/foo/events -maxdepth 1 -type f  -exec cat {} \;
> +		sleep 0.1
> +		find instances/foo/events/sched -maxdepth 1 -type f  -exec cat {} \;
> +		sleep 0.1
> +		find instances/foo/events/sched/sched_waking -maxdepth 1 -type f  -exec cat {} \;
> +		sleep 0.1
> +        done 2> /dev/null
> +}
> +
>  instance_set &
>  p1=$!
>  echo $p1
> @@ -52,15 +65,20 @@ instance_read &
>  p2=$!
>  echo $p2
>  
> +instance_cat &
> +p3=$!
> +echo $p3
> +
>  for i in `seq 10`; do
>  	instance_slam
>  done
>  
> +kill -1 $p3
>  kill -1 $p2
>  kill -1 $p1
>  
>  echo "Wait for processes to finish"
> -wait $p1 $p2
> +wait $p1 $p2 $p3
>  echo "all processes finished, wait for cleanup"
>  sleep 1
>  
> -- 
> 2.53.0
>

-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>