diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-03-14 13:13:45 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-03-15 00:36:09 -0400 |
| commit | 8aacf017b065a805d27467843490c976835eb4a5 (patch) | |
| tree | 3e3ee23502cf2cc6d02baa1f7625b1ef16611eda /kernel/trace/trace_clock.c | |
| parent | 328df4759c03e2c3e7429cc6cb0e180c38f32063 (diff) | |
tracing: Add "uptime" trace clock that uses jiffies
Add a simple trace clock called "uptime" for those that are
interested in the uptime of the trace. It uses jiffies as that's
the safest method, as other uptime clocks grab seq locks, which could
cause a deadlock if taken from an event or function tracer.
Requested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_clock.c')
| -rw-r--r-- | kernel/trace/trace_clock.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c index aa8f5f48dae..26dc348332b 100644 --- a/kernel/trace/trace_clock.c +++ b/kernel/trace/trace_clock.c @@ -57,6 +57,16 @@ u64 notrace trace_clock(void) return local_clock(); } +/* + * trace_jiffy_clock(): Simply use jiffies as a clock counter. + */ +u64 notrace trace_clock_jiffies(void) +{ + u64 jiffy = jiffies - INITIAL_JIFFIES; + + /* Return nsecs */ + return (u64)jiffies_to_usecs(jiffy) * 1000ULL; +} /* * trace_clock_global(): special globally coherent trace clock |