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 > Signed-off-by: Changbin Du <[email protected]> > --- > 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
