diff options
| author | Changbin Du <[email protected]> | 2020-08-08 10:31:38 +0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <[email protected]> | 2020-08-14 09:34:05 -0300 |
| commit | 6555c2f6db2196ef1b6d7149e7d342d0ba2ec57e (patch) | |
| tree | 8947f6bf842991b0c7af88b5cf4e77c087a939b4 | |
| parent | a8f87a5cb466888bb70330b9ba55cdc0b9a1c20e (diff) | |
perf ftrace: Add option -D/--delay to delay tracing
This adds an option '-D/--delay' to allow us to start tracing some times
later after workload is launched.
Signed-off-by: Changbin Du <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
| -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() }; |