When PREEMPT_TRACER and IRQSOFF_TRACER are both configured and irqsoff
tracer is running, the preempt_off sections might also be traced.
Thanks to Andrew Morton for pointing out my mistake of spin_lock disabling
interrupts while he was reviewing ftrace.txt. Seems that my example I used
actually hit this bug.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
#ifdef CONFIG_PREEMPT_TRACER
void trace_preempt_on(unsigned long a0, unsigned long a1)
{
- stop_critical_timing(a0, a1);
+ if (preempt_trace())
+ stop_critical_timing(a0, a1);
}
void trace_preempt_off(unsigned long a0, unsigned long a1)
{
- start_critical_timing(a0, a1);
+ if (preempt_trace())
+ start_critical_timing(a0, a1);
}
#endif /* CONFIG_PREEMPT_TRACER */