This adds an option '--inherit' to allow us trace children processes spawned by our target.
Signed-off-by: Changbin Du <[email protected]> --- 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 a18d640e90bb..66876e79cc24 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -64,6 +64,9 @@ OPTIONS --buffer-size:: Set the size of per-cpu tracing buffer in KB. +--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 686d744d5025..b2651b9bd6d0 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -40,6 +40,7 @@ struct perf_ftrace { int graph_depth; unsigned initial_delay; unsigned buffer_size_kb; + bool inherit; }; struct filter_entry { @@ -178,9 +179,27 @@ 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) @@ -199,6 +218,7 @@ 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_buffer_size_kb(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; + } + if (write_tracing_file("current_tracer", ftrace->tracer) < 0) { pr_err("failed to set current_tracer to %s\n", ftrace->tracer); goto out_reset; @@ -580,6 +616,8 @@ int cmd_ftrace(int argc, const char **argv) "ms to wait before starting tracing after program start"), OPT_UINTEGER('m', "buffer-size", &ftrace.buffer_size_kb, "size of per cpu buffer in kb"), + OPT_BOOLEAN(0, "inherit", &ftrace.inherit, + "trace children processes"), OPT_END() }; -- 2.25.1
