Messages in this thread | | | Date | Sat, 6 Jun 2020 22:37:17 +0800 | From | Changbin Du <> | Subject | Re: [PATCH 15/19] perf ftrace: show trace column header |
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On Wed, May 20, 2020 at 06:11:01PM -0300, Arnaldo Carvalho de Melo wrote: > Em Sun, May 10, 2020 at 11:06:24PM +0800, Changbin Du escreveu: > > This makes perf-ftrace display column header before printing trace. > > [acme@five perf]$ perf report -h header > > Usage: perf report [<options>] > > --header Show data header. > --header-only Show only data header. > > [acme@five perf]$ > > Perhaps there is value in --header-only to show the default that will be > setup when using some set of options. > Arnaldo, what is the '--header-only' option used for? As for ftrace, the header format is different for different trace options.
> - Arnaldo > > > $ 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 > > > > -- > > - Arnaldo
-- Cheers, Changbin Du
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