| /* |
| * trace event based perf counter profiling |
| * |
| * Copyright (C) 2009 Red Hat Inc, Peter Zijlstra <pzijlstr@redhat.com> |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include "trace.h" |
| |
| static int ftrace_profile_enable_event(struct ftrace_event_call *event) |
| { |
| if (atomic_inc_return(&event->profile_count)) |
| return 0; |
| |
| return event->profile_enable(); |
| } |
| |
| int ftrace_profile_enable(int event_id) |
| { |
| struct ftrace_event_call *event; |
| int ret = -EINVAL; |
| |
| mutex_lock(&event_mutex); |
| list_for_each_entry(event, &ftrace_events, list) { |
| if (event->id == event_id && event->profile_enable && |
| try_module_get(event->mod)) { |
| ret = ftrace_profile_enable_event(event); |
| break; |
| } |
| } |
| mutex_unlock(&event_mutex); |
| |
| return ret; |
| } |
| |
| static void ftrace_profile_disable_event(struct ftrace_event_call *event) |
| { |
| if (!atomic_add_negative(-1, &event->profile_count)) |
| return; |
| |
| event->profile_disable(); |
| } |
| |
| void ftrace_profile_disable(int event_id) |
| { |
| struct ftrace_event_call *event; |
| |
| mutex_lock(&event_mutex); |
| list_for_each_entry(event, &ftrace_events, list) { |
| if (event->id == event_id) { |
| ftrace_profile_disable_event(event); |
| module_put(event->mod); |
| break; |
| } |
| } |
| mutex_unlock(&event_mutex); |
| } |