Re: [PATCH v2 11/14] ftrace/selftest: Have the reset_trigger code be a bit more careful

[Masami Hiramatsu <mhiramat@kernel.org>]

On Mon, 14 May 2018 16:58:56 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> 
> The trigger code is picky in how it can be disabled as there may be
> dependencies between different events and synthetic events. Change the order
> on how triggers are reset.
> 
>  1) Reset triggers of all synthetic events first
>  2) Remove triggers with actions attached to them
>  3) Remove all other triggers
> 
> If this order isn't followed, then some triggers will not be reset, and an
> error may happen because a trigger is busy.

Ah, right!

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

I think this should go into stable tree too.

Thank you!

> 
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> ---
>  .../testing/selftests/ftrace/test.d/functions | 21 ++++++++++++++++---
>  1 file changed, 18 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions
> index 2a4f16fc9819..8393b1c06027 100644
> --- a/tools/testing/selftests/ftrace/test.d/functions
> +++ b/tools/testing/selftests/ftrace/test.d/functions
> @@ -15,14 +15,29 @@ reset_tracer() { # reset the current tracer
>      echo nop > current_tracer
>  }
>  
> -reset_trigger() { # reset all current setting triggers
> -    grep -v ^# events/*/*/trigger |
> +reset_trigger_file() {
> +    # remove action triggers first
> +    grep -H ':on[^:]*(' $@ |
> +    while read line; do
> +        cmd=`echo $line | cut -f2- -d: | cut -f1 -d" "`
> +	file=`echo $line | cut -f1 -d:`
> +	echo "!$cmd" >> $file
> +    done
> +    grep -Hv ^# $@ |
>      while read line; do
>          cmd=`echo $line | cut -f2- -d: | cut -f1 -d" "`
> -	echo "!$cmd" > `echo $line | cut -f1 -d:`
> +	file=`echo $line | cut -f1 -d:`
> +	echo "!$cmd" > $file
>      done
>  }
>  
> +reset_trigger() { # reset all current setting triggers
> +    if [ -d events/synthetic ]; then
> +        reset_trigger_file events/synthetic/*/trigger
> +    fi
> +    reset_trigger_file events/*/*/trigger
> +}
> +
>  reset_events_filter() { # reset all current setting filters
>      grep -v ^none events/*/*/filter |
>      while read line; do
> -- 
> 2.17.0
> 
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>