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perf ftrace: Add -D option for depth filter 

The -D/--graph-depth option is to set max graph depth.  The following
example traces max 2-depth of page fault handler.

  $ sudo perf ftrace -G __do_page_fault -D 2 -- hello
   ...
   0)               |  __do_page_fault() {
   0)   0.063 us    |    down_read_trylock();
   0)   0.251 us    |    find_vma();
   0)   5.374 us    |    handle_mm_fault();
   0)   0.054 us    |    up_read();
   0)   7.463 us    |  }
   ...

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170618142302.25390-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
hifive-unleashed-5.1
Namhyung Kim 2017-06-18 23:23:02 +09:00 committed by Arnaldo Carvalho de Melo
parent 78b83e8b12
commit 1096c35aa8
2 changed files with 34 additions and 0 deletions
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3
tools/perf/Documentation/perf-ftrace.txt
View File

@ -78,6 +78,9 @@ OPTIONS
This can be used more than once to specify multiple functions.
It will be passed to 'set_graph_notrace' in tracefs.
-D::
--graph-depth=::
Set max depth for function graph tracer to follow
SEE ALSO
--------

31
tools/perf/builtin-ftrace.c
View File

@ -35,6 +35,7 @@ struct perf_ftrace {
struct list_head notrace;
struct list_head graph_funcs;
struct list_head nograph_funcs;
int graph_depth;
};
struct filter_entry {
@ -129,6 +130,9 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
if (reset_tracing_cpu() < 0)
return -1;
if (write_tracing_file("max_graph_depth", "0") < 0)
return -1;
reset_tracing_filters();
return 0;
}
@ -237,6 +241,26 @@ static void reset_tracing_filters(void)
write_tracing_file("set_graph_notrace", " ");
}
static int set_tracing_depth(struct perf_ftrace *ftrace)
{
char buf[16];
if (ftrace->graph_depth == 0)
return 0;
if (ftrace->graph_depth < 0) {
pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
return -1;
}
snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);
if (write_tracing_file("max_graph_depth", buf) < 0)
return -1;
return 0;
}
static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
{
char *trace_file;
@ -284,6 +308,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
goto out_reset;
}
if (set_tracing_depth(ftrace) < 0) {
pr_err("failed to set graph depth\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;
@ -425,6 +454,8 @@ int cmd_ftrace(int argc, const char **argv)
"Set graph filter on given functions", parse_filter_func),
OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
"Set nograph filter on given functions", parse_filter_func),
OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
"Max depth for function graph tracer"),
OPT_END()
};