On Wed, May 20, 2020 at 06:08:14PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Sun, May 10, 2020 at 11:06:22PM +0800, Changbin Du escreveu:
> > This adds an option '-b/--buffer-size' to allow us set the size of per-cpu
> > tracing buffer.
>
> -m
>
sure.
> > Signed-off-by: Changbin Du <changbin...@gmail.com>
> > ---
> > tools/perf/builtin-ftrace.c | 45 ++++++++++++++++++++++++++++---------
> > 1 file changed, 35 insertions(+), 10 deletions(-)
> >
> > diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> > index 8fd95c109fe8..a93fbdac6aa4 100644
> > --- a/tools/perf/builtin-ftrace.c
> > +++ b/tools/perf/builtin-ftrace.c
> > @@ -47,6 +47,7 @@ struct perf_ftrace {
> > bool long_info;
> > unsigned tracing_thresh;
> > bool trace_children;
> > + unsigned buffer_size_kb;
> > };
> >
> > struct filter_entry {
> > @@ -187,6 +188,17 @@ 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);
> >
> > @@ -360,8 +372,6 @@ 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;
> >
> > @@ -370,9 +380,7 @@ 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;
> > @@ -419,14 +427,10 @@ static int set_tracing_long_info(struct perf_ftrace
> > *ftrace)
> >
> > static int set_tracing_thresh(struct perf_ftrace *ftrace)
> > {
> > - char buf[16];
> > -
> > if (ftrace->tracing_thresh == 0)
> > return 0;
> >
> > - snprintf(buf, sizeof(buf), "%d", ftrace->tracing_thresh);
> > -
> > - if (write_tracing_file("tracing_thresh", buf) < 0)
> > + if (write_tracing_file_int("tracing_thresh", ftrace->tracing_thresh) <
> > 0)
> > return -1;
> >
> > return 0;
> > @@ -454,6 +458,20 @@ static int set_tracing_trace_children(struct
> > perf_ftrace *ftrace)
> > return 0;
> > }
> >
> > +static int set_tracing_buffer_size_kb(struct perf_ftrace *ftrace)
> > +{
> > + int ret;
> > +
> > + if (ftrace->buffer_size_kb == 0)
> > + return 0;
> > +
> > + ret = write_tracing_file_int("buffer_size_kb", ftrace->buffer_size_kb);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return 0;
> > +}
> > +
> > static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char
> > **argv)
> > {
> > char *trace_file;
> > @@ -557,6 +575,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace,
> > int argc, const char **argv)
> > goto out_reset;
> > }
> >
> > + if (set_tracing_buffer_size_kb(ftrace) < 0) {
> > + pr_err("failed to set tracing per-cpu buffer size\n");
> > + goto out_reset;
> > + }
> > +
> > if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
> > pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
> > goto out_reset;
> > @@ -706,6 +729,8 @@ int cmd_ftrace(int argc, const char **argv)
> > "Only show functions of which the duration is greater than
> > <n>µs"),
> > OPT_BOOLEAN(0, "trace-children", &ftrace.trace_children,
> > "Trace children processes"),
> > + OPT_UINTEGER('b', "buffer-size", &ftrace.buffer_size_kb,
> > + "size of per cpu buffer in kb"),
> > OPT_END()
> > };
> >
> > --
> > 2.25.1
> >
>
> --
>
> - Arnaldo
--
Cheers,
Changbin Du
