mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-15 21:30:43 +00:00
e00bf2ec60
Like total_profile_count, struct ftrace_event_call::profile_count is protected by event_mutex, so it doesn't need to be atomic_t. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <4B1DC549.5010705@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
123 lines
2.4 KiB
C
123 lines
2.4 KiB
C
/*
|
|
* trace event based perf counter profiling
|
|
*
|
|
* Copyright (C) 2009 Red Hat Inc, Peter Zijlstra <pzijlstr@redhat.com>
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include "trace.h"
|
|
|
|
|
|
char *perf_trace_buf;
|
|
EXPORT_SYMBOL_GPL(perf_trace_buf);
|
|
|
|
char *perf_trace_buf_nmi;
|
|
EXPORT_SYMBOL_GPL(perf_trace_buf_nmi);
|
|
|
|
typedef typeof(char [FTRACE_MAX_PROFILE_SIZE]) perf_trace_t ;
|
|
|
|
/* Count the events in use (per event id, not per instance) */
|
|
static int total_profile_count;
|
|
|
|
static int ftrace_profile_enable_event(struct ftrace_event_call *event)
|
|
{
|
|
char *buf;
|
|
int ret = -ENOMEM;
|
|
|
|
if (event->profile_count++ > 0)
|
|
return 0;
|
|
|
|
if (!total_profile_count) {
|
|
buf = (char *)alloc_percpu(perf_trace_t);
|
|
if (!buf)
|
|
goto fail_buf;
|
|
|
|
rcu_assign_pointer(perf_trace_buf, buf);
|
|
|
|
buf = (char *)alloc_percpu(perf_trace_t);
|
|
if (!buf)
|
|
goto fail_buf_nmi;
|
|
|
|
rcu_assign_pointer(perf_trace_buf_nmi, buf);
|
|
}
|
|
|
|
ret = event->profile_enable(event);
|
|
if (!ret) {
|
|
total_profile_count++;
|
|
return 0;
|
|
}
|
|
|
|
fail_buf_nmi:
|
|
if (!total_profile_count) {
|
|
free_percpu(perf_trace_buf_nmi);
|
|
free_percpu(perf_trace_buf);
|
|
perf_trace_buf_nmi = NULL;
|
|
perf_trace_buf = NULL;
|
|
}
|
|
fail_buf:
|
|
event->profile_count--;
|
|
|
|
return ret;
|
|
}
|
|
|
|
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)
|
|
{
|
|
char *buf, *nmi_buf;
|
|
|
|
if (--event->profile_count > 0)
|
|
return;
|
|
|
|
event->profile_disable(event);
|
|
|
|
if (!--total_profile_count) {
|
|
buf = perf_trace_buf;
|
|
rcu_assign_pointer(perf_trace_buf, NULL);
|
|
|
|
nmi_buf = perf_trace_buf_nmi;
|
|
rcu_assign_pointer(perf_trace_buf_nmi, NULL);
|
|
|
|
/*
|
|
* Ensure every events in profiling have finished before
|
|
* releasing the buffers
|
|
*/
|
|
synchronize_sched();
|
|
|
|
free_percpu(buf);
|
|
free_percpu(nmi_buf);
|
|
}
|
|
}
|
|
|
|
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);
|
|
}
|