static ssize_t
sysprof_sample_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[MAX_LONG_DIGITS];
unsigned long val;
if (cnt > MAX_LONG_DIGITS-1)
cnt = MAX_LONG_DIGITS-1;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
val = simple_strtoul(buf, NULL, 10);
/*
* Enforce a minimum sample period of 100 usecs:
*/
if (val < 100)
val = 100;
mutex_lock(&sample_timer_lock);
stop_stack_timers();
sample_period = val * 1000;
start_stack_timers();
mutex_unlock(&sample_timer_lock);
return cnt;
}
static void start_stack_trace(struct trace_array *tr)
{
mutex_lock(&sample_timer_lock);
tracing_reset_online_cpus(tr);
start_stack_timers();
tracer_enabled = 1;
mutex_unlock(&sample_timer_lock);
}
static int stack_trace_init(struct trace_array *tr)
{
sysprof_trace = tr;
tracing_start_cmdline_record();
mutex_lock(&sample_timer_lock);
start_stack_timers();
tracer_enabled = 1;
mutex_unlock(&sample_timer_lock);
return 0;
}