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authorChunyan Zhang <zhang.chunyan@linaro.org>2015-10-27 20:12:13 +0800
committerSteven Rostedt <rostedt@goodmis.org>2015-11-02 13:34:58 -0500
commitbdb5d0f9045ed88811b6253682dff6b576dd0064 (patch)
tree3309a6e0cb5e6a8326c3e96632a5282a0b1bad90 /kernel/trace
parent46a2b61ecb286dddb4efa73b119fec54e1576efe (diff)
tracing: Only benchmark the time tracepoints take if tracing is on
There's no need to record the time tracepoints take when tracing is off. This is because: 1) We cannot see these records since ring_buffer record is off at that moment. 2) If tracing is off and benchmark tracepoint is enabled, the time tracepoint takes is fewer than the same situation when tracing is on, since the tracepoints need to be wrote into ring_buffer, it would take more time. If turn on tracing at this moment, the average and standard deviation cannot exactly present the time that tracepoints take to write data into ring_buffer. Link: http://lkml.kernel.org/r/1445947933-27955-1-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_benchmark.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c
index 40a14cbcf8e0..0f109c4130d3 100644
--- a/kernel/trace/trace_benchmark.c
+++ b/kernel/trace/trace_benchmark.c
@@ -43,7 +43,7 @@ static void trace_do_benchmark(void)
unsigned int std = 0;
/* Only run if the tracepoint is actually active */
- if (!trace_benchmark_event_enabled())
+ if (!trace_benchmark_event_enabled() || !tracing_is_on())
return;
local_irq_disable();