static void
check_critical_timing(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long parent_ip,
int cpu)
{
cycle_t T0, T1, delta;
unsigned long flags;
int pc;
T0 = data->preempt_timestamp;
T1 = ftrace_now(cpu);
delta = T1-T0;
local_save_flags(flags);
pc = preempt_count();
if (!report_latency(delta))
goto out;
atomic_spin_lock_irqsave(&max_trace_lock, flags);
/* check if we are still the max latency */
if (!report_latency(delta))
goto out_unlock;
trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
if (data->critical_sequence != max_sequence)
goto out_unlock;
data->critical_end = parent_ip;
if (likely(!is_tracing_stopped())) {
tracing_max_latency = delta;
update_max_tr_single(tr, current, cpu);
}
max_sequence++;
out_unlock:
atomic_spin_unlock_irqrestore(&max_trace_lock, flags);
out:
data->critical_sequence = max_sequence;
data->preempt_timestamp = ftrace_now(cpu);
trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
}
static void notrace
probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev,
struct task_struct *next)
{
struct trace_array_cpu *data;
cycle_t T0, T1, delta;
unsigned long flags;
long disabled;
int cpu;
int pc;
tracing_record_cmdline(prev);
if (unlikely(!tracer_enabled))
return;
/*
* When we start a new trace, we set wakeup_task to NULL
* and then set tracer_enabled = 1. We want to make sure
* that another CPU does not see the tracer_enabled = 1
* and the wakeup_task with an older task, that might
* actually be the same as next.
*/
smp_rmb();
if (next != wakeup_task)
return;
pc = preempt_count();
/* disable local data, not wakeup_cpu data */
cpu = raw_smp_processor_id();
disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled);
if (likely(disabled != 1))
goto out;
local_irq_save(flags);
__raw_spin_lock(&wakeup_lock);
/* We could race with grabbing wakeup_lock */
if (unlikely(!tracer_enabled || next != wakeup_task))
goto out_unlock;
/* The task we are waiting for is waking up */
data = wakeup_trace->data[wakeup_cpu];
trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc);
tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc);
T0 = data->preempt_timestamp;
T1 = ftrace_now(cpu);
delta = T1-T0;
if (!report_latency(delta))
goto out_unlock;
if (likely(!is_tracing_stopped())) {
tracing_max_latency = delta;
update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu);
}
out_unlock:
__wakeup_reset(wakeup_trace);
__raw_spin_unlock(&wakeup_lock);
local_irq_restore(flags);
out:
atomic_dec(&wakeup_trace->data[cpu]->disabled);
}
