On Sun, 10 Feb 2019 00:19:19 +0800 Changbin Du <[email protected]> wrote:
> Here is an example for this change. > > $ sudo perf record -e 'ftrace:function' --filter='ip==schedule' > $ sudo perf report I took this but changed the subject as it only affects perf (the kernel doesn't use the format field for output, and trace-cmd has an internal plugin that overrides it too). -- Steve > > The output of perf before this patch: > > \# Samples: 100 of event 'ftrace:function' > \# Event count (approx.): 100 > \# > \# Overhead Trace output > \# ........ ...................................... > \# > 51.00% ffffffff81f6aaa0 <-- ffffffff81158e8d > 29.00% ffffffff81f6aaa0 <-- ffffffff8116ccb2 > 8.00% ffffffff81f6aaa0 <-- ffffffff81f6f2ed > 4.00% ffffffff81f6aaa0 <-- ffffffff811628db > 4.00% ffffffff81f6aaa0 <-- ffffffff81f6ec5b > 2.00% ffffffff81f6aaa0 <-- ffffffff81f6f21a > 1.00% ffffffff81f6aaa0 <-- ffffffff811b04af > 1.00% ffffffff81f6aaa0 <-- ffffffff8143ce17 > > After this patch: > > \# Samples: 36 of event 'ftrace:function' > \# Event count (approx.): 36 > \# > \# Overhead Trace output > \# ........ ............................................ > \# > 38.89% schedule <-- schedule_hrtimeout_range_clock > 27.78% schedule <-- worker_thread > 13.89% schedule <-- schedule_timeout > 11.11% schedule <-- smpboot_thread_fn > 5.56% schedule <-- rcu_gp_kthread > 2.78% schedule <-- exit_to_usermode_loop > > Signed-off-by: Changbin Du <[email protected]> > --- > kernel/trace/trace_entries.h | 41 +++++++++++++++++------------------- > 1 file changed, 19 insertions(+), 22 deletions(-) > >
