[for-next][PATCH 8/8] tracing: Remove redundant reset per-CPU buff in irqsoff tracer

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From	Steven Rostedt <rostedt@goodmis.org>
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Subject	[for-next][PATCH 8/8] tracing: Remove redundant reset per-CPU buff in irqsoff tracer
Date	Sat, 19 Mar 2016 15:20:02 +0100
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From: Dmitry Safonov <0x7f454c46@gmail.com>

  There is no reason to do it twice: from commit b6f11df26fdc28
("trace: Call tracing_reset_online_cpus before tracer->init()")
resetting of per-CPU buffers done before tracer->init() call.

tracer->init() calls {irqs,preempt,preemptirqs}off_tracer_init() and it
calls __irqsoff_tracer_init(), which resets per-CPU ringbuffer second
time.
It's slowpath, but anyway.

Link: http://lkml.kernel.org/r/1445278226-16187-1-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_irqsoff.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index be3222b7d72e..03cdff84d026 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -626,7 +626,6 @@ static int __irqsoff_tracer_init(struct trace_array *tr)
 	irqsoff_trace = tr;
 	/* make sure that the tracer is visible */
 	smp_wmb();
-	tracing_reset_online_cpus(&tr->trace_buffer);
 
 	ftrace_init_array_ops(tr, irqsoff_tracer_call);
 
-- 
2.7.0

Thread

[for-next][PATCH 0/8] tracing: Last minute updates for 4.6 Steven Rostedt <rostedt@goodmis.org> - 2016-03-19 15:20 +0100
  [for-next][PATCH 2/8] ftrace: Update dynamic ftrace calls only if necessary Steven Rostedt <rostedt@goodmis.org> - 2016-03-19 15:20 +0100
  [for-next][PATCH 8/8] tracing: Remove redundant reset per-CPU buff in irqsoff tracer Steven Rostedt <rostedt@goodmis.org> - 2016-03-19 15:20 +0100
  [for-next][PATCH 7/8] x86: ftrace: Fix the misleading comment for arch/x86/kernel/ftrace.c Steven Rostedt <rostedt@goodmis.org> - 2016-03-19 15:20 +0100

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