From 81523c1e579bb95106e22b864fbef687d585f2b9 Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Sat, 8 Aug 2020 10:31:28 +0800 Subject: perf ftrace: Show trace column header 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 Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Steven Rostedt (VMware) Link: http://lore.kernel.org/lkml/20200808023141.14227-6-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-ftrace.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'tools') diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index a3a4f4be9dde..39c694be2b71 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -435,6 +435,9 @@ 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; -- cgit v1.2.3