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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-03-14 16:10:40 (GMT) |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-03-15 04:36:08 (GMT) |
| commit | 328df4759c03e2c3e7429cc6cb0e180c38f32063 (patch) | |
| tree | 874c0aa7642cfe8ce1e4512464eae1d33e99391b /kernel/trace/trace.c | |
| parent | 4df297129f622bdc18935c856f42b9ddd18f9f28 (diff) | |
| download | linux-fsl-qoriq-328df4759c03e2c3e7429cc6cb0e180c38f32063.tar.xz | |
tracing: Add function-trace option to disable function tracing of latency tracers
Currently, the only way to stop the latency tracers from doing function
tracing is to fully disable the function tracer from the proc file
system:
echo 0 > /proc/sys/kernel/ftrace_enabled
This is a big hammer approach as it disables function tracing for
all users. This includes kprobes, perf, stack tracer, etc.
Instead, create a function-trace option that the latency tracers can
check to determine if it should enable function tracing or not.
This option can be set or cleared even while the tracer is active
and the tracers will disable or enable function tracing depending
on how the option was set.
Instead of using the proc file, disable latency function tracing with
echo 0 > /debug/tracing/options/function-trace
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8aa5321..f90ca16 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -328,7 +328,7 @@ static inline void trace_access_lock_init(void) unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | - TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS; + TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS | TRACE_ITER_FUNCTION; /** * tracing_on - enable tracing buffers @@ -635,6 +635,7 @@ static const char *trace_options[] = { "disable_on_free", "irq-info", "markers", + "function-trace", NULL }; |