| From | Changbin Du <> | Subject | [PATCH 15/19] perf ftrace: show trace column header | Date | Sun, 10 May 2020 23:06:24 +0800 |
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This makes perf-ftrace display column header before printing trace.
$ sudo perf ftrace \# tracer: function \# \# entries-in-buffer/entries-written: 0/0 #P:8 \# \# TASK-PID CPU# TIMESTAMP FUNCTION \# | | | | | <...>-9246 [006] 10726.262760: mutex_unlock <-rb_simple_write <...>-9246 [006] 10726.262764: __fsnotify_parent <-vfs_write <...>-9246 [006] 10726.262765: fsnotify <-vfs_write <...>-9246 [006] 10726.262766: __sb_end_write <-vfs_write <...>-9246 [006] 10726.262767: fpregs_assert_state_consistent <-do_syscall_64
Signed-off-by: Changbin Du <changbin.du@gmail.com> --- tools/perf/builtin-ftrace.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 64c22f367ba2..0b39b6a88026 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -614,6 +614,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) fcntl(trace_fd, F_SETFL, O_NONBLOCK); pollfd.fd = trace_fd; + /* 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; -- 2.25.1
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