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perf ftrace: Add support for tracing option 'func_stack_trace'

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This adds support to display call trace for function tracer. To do this,
just specify a '--func-opts call-graph' option.

Example:

  $ sudo perf ftrace -T vfs_read --func-opts call-graph
   iio-sensor-prox-855   [003]   6168.369657: vfs_read <-ksys_read
   iio-sensor-prox-855   [003]   6168.369677: <stack trace>
   => vfs_read
   => ksys_read
   => __x64_sys_read
   => do_syscall_64
   => entry_SYSCALL_64_after_hwframe
   ...

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: http://lore.kernel.org/lkml/20200808023141.14227-9-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Changbin Du 2020-08-08 10:31:31 +08:00 committed by Arnaldo Carvalho de Melo
parent a80abe2a9a
commit b1d84af6f5
2 changed files with 46 additions and 0 deletions
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4
tools/perf/Documentation/perf-ftrace.txt
View File

@ -76,6 +76,10 @@ OPTIONS
specify multiple functions (or glob patterns). It will be
passed to 'set_ftrace_notrace' in tracefs.
--func-opts::
List of options allowed to set:
call-graph - Display kernel stack trace for function tracer.
-G::
--graph-funcs=::
Select function_graph tracer and set graph filter on the given

42
tools/perf/builtin-ftrace.c
View File

@ -27,6 +27,7 @@
#include "util/cap.h"
#include "util/config.h"
#include "util/units.h"
#include "util/parse-sublevel-options.h"
#define DEFAULT_TRACER "function_graph"
@ -42,6 +43,7 @@ struct perf_ftrace {
int graph_depth;
unsigned long percpu_buffer_size;
bool inherit;
int func_stack_trace;
};
struct filter_entry {
@ -202,6 +204,7 @@ static void reset_tracing_filters(void);
static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
{
write_tracing_option_file("function-fork", "0");
write_tracing_option_file("func_stack_trace", "0");
}
static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
@ -278,6 +281,17 @@ static int set_tracing_cpu(struct perf_ftrace *ftrace)
return set_tracing_cpumask(cpumap);
}
static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
{
if (!ftrace->func_stack_trace)
return 0;
if (write_tracing_option_file("func_stack_trace", "1") < 0)
return -1;
return 0;
}
static int reset_tracing_cpu(void)
{
struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
@ -426,6 +440,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
goto out_reset;
}
if (set_tracing_func_stack_trace(ftrace) < 0) {
pr_err("failed to set tracing option func_stack_trace\n");
goto out_reset;
}
if (set_tracing_filters(ftrace) < 0) {
pr_err("failed to set tracing filters\n");
goto out_reset;
@ -598,6 +617,26 @@ static int parse_buffer_size(const struct option *opt,
return -1;
}
static int parse_func_tracer_opts(const struct option *opt,
const char *str, int unset)
{
int ret;
struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
struct sublevel_option func_tracer_opts[] = {
{ .name = "call-graph", .value_ptr = &ftrace->func_stack_trace },
{ .name = NULL, }
};
if (unset)
return 0;
ret = perf_parse_sublevel_options(str, func_tracer_opts);
if (ret)
return ret;
return 0;
}
static void select_tracer(struct perf_ftrace *ftrace)
{
bool graph = !list_empty(&ftrace->graph_funcs) ||
@ -645,6 +684,9 @@ int cmd_ftrace(int argc, const char **argv)
parse_filter_func),
OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
"do not trace given functions", parse_filter_func),
OPT_CALLBACK(0, "func-opts", &ftrace, "options",
"function tracer options, available options: call-graph",
parse_func_tracer_opts),
OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
"trace given functions using function_graph tracer",
parse_filter_func),