diff options
| -rw-r--r-- | tools/perf/Documentation/perf-ftrace.txt | 4 | ||||
| -rw-r--r-- | tools/perf/builtin-ftrace.c | 19 |
2 files changed, 20 insertions, 3 deletions
diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index 08216634d2bc..29c684b3b3fd 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -39,6 +39,10 @@ OPTIONS --pid=:: Trace on existing process id (comma separated list). +-D:: +--delay:: + Time (ms) to wait before starting tracing after program start. + -a:: --all-cpus:: Force system-wide collection. Scripts run without a <command> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index bc3b35d18167..5f9a9ebea0a2 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -49,6 +49,7 @@ struct perf_ftrace { int graph_noirqs; int graph_verbose; int graph_thresh; + unsigned int initial_delay; }; struct filter_entry { @@ -596,13 +597,23 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) /* display column headers */ read_tracing_file_to_stdout("trace"); - if (write_tracing_file("tracing_on", "1") < 0) { - pr_err("can't enable tracing\n"); - goto out_close_fd; + if (!ftrace->initial_delay) { + if (write_tracing_file("tracing_on", "1") < 0) { + pr_err("can't enable tracing\n"); + goto out_close_fd; + } } perf_evlist__start_workload(ftrace->evlist); + if (ftrace->initial_delay) { + usleep(ftrace->initial_delay * 1000); + if (write_tracing_file("tracing_on", "1") < 0) { + pr_err("can't enable tracing\n"); + goto out_close_fd; + } + } + while (!done) { if (poll(&pollfd, 1, -1) < 0) break; @@ -827,6 +838,8 @@ int cmd_ftrace(int argc, const char **argv) "size of per cpu buffer", parse_buffer_size), OPT_BOOLEAN(0, "inherit", &ftrace.inherit, "trace children processes"), + OPT_UINTEGER('D', "delay", &ftrace.initial_delay, + "ms to wait before starting tracing after program start"), OPT_END() }; |