From 1e10486ffee0a5b060c58b9c8c712422f7b88b3b Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Mon, 17 Apr 2017 11:44:28 +0900 Subject: ftrace: Add 'function-fork' trace option The function-fork option is same as event-fork that it tracks task fork/exit and set the pid filter properly. This can be useful if user wants to trace selected tasks including their children only. Link: http://lkml.kernel.org/r/20170417024430.21194-3-namhyung@kernel.org Signed-off-by: Namhyung Kim Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ftrace.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'kernel/trace/ftrace.c') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index b21a3e61ac74..b5ce7ea67e02 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5600,6 +5600,43 @@ ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, trace_ignore_this_task(pid_list, next)); } +static void +ftrace_pid_follow_sched_process_fork(void *data, + struct task_struct *self, + struct task_struct *task) +{ + struct trace_pid_list *pid_list; + struct trace_array *tr = data; + + pid_list = rcu_dereference_sched(tr->function_pids); + trace_filter_add_remove_task(pid_list, self, task); +} + +static void +ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) +{ + struct trace_pid_list *pid_list; + struct trace_array *tr = data; + + pid_list = rcu_dereference_sched(tr->function_pids); + trace_filter_add_remove_task(pid_list, NULL, task); +} + +void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) +{ + if (enable) { + register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, + tr); + register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, + tr); + } else { + unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, + tr); + unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, + tr); + } +} + static void clear_ftrace_pids(struct trace_array *tr) { struct trace_pid_list *pid_list; -- cgit v1.2.3