lkml.org 
[lkml]   [2020]   [Jul]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v5 07/17] perf ftrace: add option '--inherit' to trace children processes
On Mon, Jul 13, 2020 at 10:59:56AM +0900, Namhyung Kim wrote:
> On Sat, Jul 11, 2020 at 9:42 PM Changbin Du <changbin.du@gmail.com> wrote:
> >
> > This adds an option '--inherit' to allow us trace children
> > processes spawned by our target.
> >
> > Signed-off-by: Changbin Du <changbin.du@gmail.com>
> >
> > ---
> > v2: option name '--trace-children' -> '--inherit'.
> > ---
> > tools/perf/Documentation/perf-ftrace.txt | 3 ++
> > tools/perf/builtin-ftrace.c | 38 ++++++++++++++++++++++++
> > 2 files changed, 41 insertions(+)
> >
> > diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
> > index 98fe01d354d1..fd632bd9b2c1 100644
> > --- a/tools/perf/Documentation/perf-ftrace.txt
> > +++ b/tools/perf/Documentation/perf-ftrace.txt
> > @@ -61,6 +61,9 @@ OPTIONS
> > Set the size of per-cpu tracing buffer, <size> is expected to
> > be a number with appended unit character - B/K/M/G.
> >
> > +--inherit::
> > + Trace children processes spawned by our target.
> > +
> > -T::
> > --trace-funcs=::
> > Only trace functions given by the argument. Multiple functions
> > diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> > index 887e78b23a82..4efaa7b6a906 100644
> > --- a/tools/perf/builtin-ftrace.c
> > +++ b/tools/perf/builtin-ftrace.c
> > @@ -39,6 +39,7 @@ struct perf_ftrace {
> > struct list_head nograph_funcs;
> > int graph_depth;
> > unsigned long percpu_buffer_size;
> > + bool inherit;
> > };
> >
> > struct filter_entry {
> > @@ -177,9 +178,27 @@ static int write_tracing_file_int(const char *name, int value)
> > return 0;
> > }
> >
> > +static int write_tracing_option_file(const char *name, const char *val)
> > +{
> > + char *file;
> > + int ret;
> > +
> > + if (asprintf(&file, "options/%s", name) < 0)
> > + return -1;
> > +
> > + ret = __write_tracing_file(file, val, false);
> > + free(file);
> > + return ret;
> > +}
> > +
> > static int reset_tracing_cpu(void);
> > static void reset_tracing_filters(void);
> >
> > +static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
> > +{
> > + write_tracing_option_file("function-fork", "0");
> > +}
> > +
> > static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
> > {
> > if (write_tracing_file("tracing_on", "0") < 0)
> > @@ -198,6 +217,7 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
> > return -1;
> >
> > reset_tracing_filters();
> > + reset_tracing_options(ftrace);
> > return 0;
> > }
> >
> > @@ -336,6 +356,17 @@ static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace)
> > return 0;
> > }
> >
> > +static int set_tracing_trace_inherit(struct perf_ftrace *ftrace)
> > +{
> > + if (!ftrace->inherit)
> > + return 0;
> > +
> > + if (write_tracing_option_file("function-fork", "1") < 0)
> > + return -1;
> > +
> > + return 0;
> > +}
> > +
> > static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
> > {
> > char *trace_file;
> > @@ -405,6 +436,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
> > goto out_reset;
> > }
> >
> > + if (set_tracing_trace_inherit(ftrace) < 0) {
> > + pr_err("failed to set tracing option function-fork\n");
> > + goto out_reset;
> > + }
>
> Can we have set_tracing_options() here instead to make
> the __cmd_ftrace() shorter? It'd set other options added later.
> It's also symmetric to reset_tracing_options().
>
I appended a patch to do this. Thanks for your suggestion.

> Thanks
> Namhyung
>
> > +
> > if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
> > pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
> > goto out_reset;
> > @@ -599,6 +635,8 @@ int cmd_ftrace(int argc, const char **argv)
> > "Max depth for function graph tracer"),
> > OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
> > "size of per cpu buffer", parse_buffer_size),
> > + OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
> > + "trace children processes"),
> > OPT_END()
> > };
> >
> > --
> > 2.25.1
> >

--
Cheers,
Changbin Du

\
 
 \ /
  Last update: 2020-07-17 16:28    [W:0.058 / U:0.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site