OpenCloudOS-Kernel/kernel/trace/trace_nop.c

65 lines
1.1 KiB
C

/*
* nop tracer
*
* Copyright (C) 2008 Steven Noonan <steven@uplinklabs.net>
*
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/ftrace.h>
#include "trace.h"
static struct trace_array *ctx_trace;
static void start_nop_trace(struct trace_array *tr)
{
/* Nothing to do! */
}
static void stop_nop_trace(struct trace_array *tr)
{
/* Nothing to do! */
}
static void nop_trace_init(struct trace_array *tr)
{
int cpu;
ctx_trace = tr;
for_each_online_cpu(cpu)
tracing_reset(tr->data[cpu]);
if (tr->ctrl)
start_nop_trace(tr);
}
static void nop_trace_reset(struct trace_array *tr)
{
if (tr->ctrl)
stop_nop_trace(tr);
}
static void nop_trace_ctrl_update(struct trace_array *tr)
{
/* When starting a new trace, reset the buffers */
if (tr->ctrl)
start_nop_trace(tr);
else
stop_nop_trace(tr);
}
struct tracer nop_trace __read_mostly =
{
.name = "nop",
.init = nop_trace_init,
.reset = nop_trace_reset,
.ctrl_update = nop_trace_ctrl_update,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_nop,
#endif
};