Re: [PATCH] tracing: use match_string() to simplify the code

[Steven Rostedt]

On Tue, 5 Jun 2018 19:32:57 +0300
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:

> On Thu, May 17, 2018 at 11:36 AM, Yisheng Xie <xieyisheng1@xxxxxxxxxx> wrote:
> > match_string() returns the index of an array for a matching string,
> > which can be used to simplify the code.
> >  
> 
> FWIW,
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

Thanks for the reminder, I was going to add this patch, but haven't
gotten to it.

-- Steve

> 
> > Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
> > ---
> >  kernel/trace/trace.c | 15 +++++----------
> >  1 file changed, 5 insertions(+), 10 deletions(-)
> >
> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > index 414d721..4bd653a 100644
> > --- a/kernel/trace/trace.c
> > +++ b/kernel/trace/trace.c
> > @@ -4395,8 +4395,7 @@ static int trace_set_options(struct trace_array *tr, char *option)
> >  {
> >         char *cmp;
> >         int neg = 0;
> > -       int ret = -ENODEV;
> > -       int i;
> > +       int ret;
> >         size_t orig_len = strlen(option);
> >
> >         cmp = strstrip(option);
> > @@ -4408,16 +4407,12 @@ static int trace_set_options(struct trace_array *tr, char *option)
> >
> >         mutex_lock(&trace_types_lock);
> >
> > -       for (i = 0; trace_options[i]; i++) {
> > -               if (strcmp(cmp, trace_options[i]) == 0) {
> > -                       ret = set_tracer_flag(tr, 1 << i, !neg);
> > -                       break;
> > -               }
> > -       }
> > -
> > +       ret = match_string(trace_options, -1, cmp);
> >         /* If no option could be set, test the specific tracer options */
> > -       if (!trace_options[i])
> > +       if (ret < 0)
> >                 ret = set_tracer_option(tr, cmp, neg);
> > +       else
> > +               ret = set_tracer_flag(tr, 1 << ret, !neg);
> >
> >         mutex_unlock(&trace_types_lock);
> >
> > --
> > 1.7.12.4
> >  
> 
> 
>