On Tue, Jul 07, 2020 at 12:09:23PM -0400, Steven Rostedt wrote:
> On Sat, 27 Jun 2020 21:36:44 +0800
> Changbin Du <changbin...@gmail.com> wrote:
>
> > We will reuse this function later.
> >
>
> BTW, trace-cmd.git now has a libtracefs.so library, which I'm hoping
> within a month to have as a stand alone (probably along with
> libtraceevent and even a libtracecmd).
>
>
> https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git/tree/lib/tracefs
>
> This is a library made to interact with the tracefs directory to remove
> reimplementing it all over the place.
>
Nice! This will make implementing a tracing tool much simpler. Look forward
to seeing it appears in most Linux distributions.
> -- Steve
>
>
>
> > Signed-off-by: Changbin Du <changbin...@gmail.com>
> > ---
> > tools/perf/builtin-ftrace.c | 17 ++++++++++++-----
> > 1 file changed, 12 insertions(+), 5 deletions(-)
> >
> > diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> > index dceae70c3a22..003efa756322 100644
> > --- a/tools/perf/builtin-ftrace.c
> > +++ b/tools/perf/builtin-ftrace.c
> > @@ -166,6 +166,17 @@ static int read_tracing_file_to_stdout(const char
> > *name)
> > return ret;
> > }
> >
> > +static int write_tracing_file_int(const char *name, int value)
> > +{
> > + char buf[16];
> > +
> > + snprintf(buf, sizeof(buf), "%d", value);
> > + if (write_tracing_file(name, buf) < 0)
> > + return -1;
> > +
> > + return 0;
> > +}
> > +
> > static int reset_tracing_cpu(void);
> > static void reset_tracing_filters(void);
> >
> > @@ -296,8 +307,6 @@ static void reset_tracing_filters(void)
> >
> > static int set_tracing_depth(struct perf_ftrace *ftrace)
> > {
> > - char buf[16];
> > -
> > if (ftrace->graph_depth == 0)
> > return 0;
> >
> > @@ -306,9 +315,7 @@ static int set_tracing_depth(struct perf_ftrace *ftrace)
> > return -1;
> > }
> >
> > - snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);
> > -
> > - if (write_tracing_file("max_graph_depth", buf) < 0)
> > + if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0)
> > return -1;
> >
> > return 0;
>
--
Cheers,
Changbin Du
