tracing: Add support for preempt and irq enable/disable events

Preempt and irq trace events can be used for tracing the start and
end of an atomic section which can be used by a trace viewer like
systrace to graphically view the start and end of an atomic section and
correlate them with latencies and scheduling issues.

This also serves as a prelude to using synthetic events or probes to
rewrite the preempt and irqsoff tracers, along with numerous benefits of
using trace events features for these events.
Link: http://lkml.kernel.org/r/20171006005432.14244-3-joelaf@google.com
Link: http://lkml.kernel.org/r/20171010225137.17370-1-joelaf@google.com

Cc: Peter Zilstra <peterz@infradead.org>
Cc: kernel-team@android.com
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Joel Fernandes 2017-10-10 15:51:37 -07:00 committed by Steven Rostedt (VMware)
parent aaecaa0b5f
commit d59158162e
5 changed files with 118 additions and 2 deletions

View file

@ -769,7 +769,8 @@ static inline unsigned long get_lock_parent_ip(void)
static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
#endif
#ifdef CONFIG_PREEMPT_TRACER
#if defined(CONFIG_PREEMPT_TRACER) || \
(defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_PREEMPTIRQ_EVENTS))
extern void trace_preempt_on(unsigned long a0, unsigned long a1);
extern void trace_preempt_off(unsigned long a0, unsigned long a1);
#else