Commit 1e01cb0c authored Jul 15, 2008 by Steven Rostedt Committed by Ingo Molnar Jul 18, 2008

ftrace: only trace preempt off with preempt tracer



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>

parent e59494f4

kernel/trace/trace_irqsoff.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -337,11 +337,13 @@ EXPORT_SYMBOL(trace_hardirqs_off_caller);
		#ifdef CONFIG_PREEMPT_TRACER
		void trace_preempt_on(unsigned long a0, unsigned long a1)
		{
		if (preempt_trace())
		stop_critical_timing(a0, a1);
		}

		void trace_preempt_off(unsigned long a0, unsigned long a1)
		{
		if (preempt_trace())
		start_critical_timing(a0, a1);
		}
		#endif /* CONFIG_PREEMPT_TRACER */