+1
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ftrace: Add set_graph_notrace filter
The set_graph_notrace filter is analogous to set_ftrace_notrace and
can be used for eliminating uninteresting part of function graph trace
output. It also works with set_graph_function nicely.
# cd /sys/kernel/debug/tracing/
# echo do_page_fault > set_graph_function
# perf ftrace live true
2) | do_page_fault() {
2) | __do_page_fault() {
2) 0.381 us | down_read_trylock();
2) 0.055 us | __might_sleep();
2) 0.696 us | find_vma();
2) | handle_mm_fault() {
2) | handle_pte_fault() {
2) | __do_fault() {
2) | filemap_fault() {
2) | find_get_page() {
2) 0.033 us | __rcu_read_lock();
2) 0.035 us | __rcu_read_unlock();
2) 1.696 us | }
2) 0.031 us | __might_sleep();
2) 2.831 us | }
2) | _raw_spin_lock() {
2) 0.046 us | add_preempt_count();
2) 0.841 us | }
2) 0.033 us | page_add_file_rmap();
2) | _raw_spin_unlock() {
2) 0.057 us | sub_preempt_count();
2) 0.568 us | }
2) | unlock_page() {
2) 0.084 us | page_waitqueue();
2) 0.126 us | __wake_up_bit();
2) 1.117 us | }
2) 7.729 us | }
2) 8.397 us | }
2) 8.956 us | }
2) 0.085 us | up_read();
2) + 12.745 us | }
2) + 13.401 us | }
...
# echo handle_mm_fault > set_graph_notrace
# perf ftrace live true
1) | do_page_fault() {
1) | __do_page_fault() {
1) 0.205 us | down_read_trylock();
1) 0.041 us | __might_sleep();
1) 0.344 us | find_vma();
1) 0.069 us | up_read();
1) 4.692 us | }
1) 5.311 us | }
...
Link: http://lkml.kernel.org/r/1381739066-7531-5-git-send-email-namhyung@kernel.org
Signed-off-by: 
Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>