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authorNamhyung Kim <namhyung@kernel.org>2017-02-24 04:12:48 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2017-03-04 01:07:16 +0300
commita9af6be5bc25214f7870fef2b6d3490fe8b87bf7 (patch)
tree9a331051dcbd39c05f6645751577ace1ff61f22e /tools/perf/Documentation/perf-ftrace.txt
parent7768f8dada66d6052fccbc2ddc375f3e650455b9 (diff)
downloadlinux-a9af6be5bc25214f7870fef2b6d3490fe8b87bf7.tar.xz
perf ftrace: Add support for --pid option
The -p (--pid) option enables to trace existing process by its pid. Committer notes: Testing it: Using the function_graph tracer on a process that is just waiting for user input and thus will make 'perf ftrace' sit there waiting for that, then press any key on that mutt session and see what happens: # perf ftrace -t function_graph -p `pidof mutt` | head -40 2) 1.038 us | switch_mm_irqs_off(); ------------------------------------------ 2) <idle>-0 => mutt-3595 ------------------------------------------ 2) | finish_task_switch() { 2) | smp_irq_work_interrupt() { 2) | irq_enter() { 2) 0.180 us | rcu_irq_enter(); 2) 1.248 us | } 2) | __wake_up() { 2) 0.126 us | _raw_spin_lock_irqsave(); 2) | __wake_up_common() { 2) | pollwake() { 2) | default_wake_function() { 2) | try_to_wake_up() { 2) 0.662 us | _raw_spin_lock_irqsave(); 2) | select_task_rq_fair() { 2) 1.719 us | effective_load.isra.41(); 2) 1.343 us | effective_load.isra.41(); 2) | select_idle_sibling() { 2) 0.331 us | idle_cpu(); 2) 1.458 us | } 2) 8.350 us | } 2) 0.200 us | _raw_spin_lock(); 2) | ttwu_do_activate() { 2) | activate_task() { 2) 0.136 us | update_rq_clock.part.77(); 2) | enqueue_task_fair() { 2) | enqueue_entity() { 2) 0.146 us | update_curr(); 2) 0.330 us | account_entity_enqueue(); 2) 0.280 us | update_cfs_shares(); 2) 0.321 us | place_entity(); 2) 0.206 us | __enqueue_entity(); 2) 6.926 us | } 2) | enqueue_entity() { 2) 0.105 us | update_curr(); 2) 0.175 us | account_entity_enqueue(); 2) 0.531 us | update_cfs_shares(); # Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170224011251.14946-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation/perf-ftrace.txt')
-rw-r--r--tools/perf/Documentation/perf-ftrace.txt4
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 2d96de6132a9..2d39397f3f30 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -30,6 +30,10 @@ OPTIONS
--verbose=::
Verbosity level.
+-p::
+--pid=::
+ Trace on existing process id (comma separated list).
+
SEE ALSO
--------