Commit 30c93704 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

tracing: Use CONFIG_PREEMPTION 



CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.

Switch the conditionals in the tracer over to CONFIG_PREEMPTION.

This is the first step to make the tracer work on RT. The other small
tweaks are submitted separately.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190726212124.409766323@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 27972765

kernel/trace/Kconfig

+2 −2
Original line number Diff line number Diff line
@@ -179,7 +179,7 @@ config TRACE_PREEMPT_TOGGLE 
config PREEMPTIRQ_EVENTS

	bool "Enable trace events for preempt and irq disable/enable"

	select TRACE_IRQFLAGS

	select TRACE_PREEMPT_TOGGLE if PREEMPT

	select TRACE_PREEMPT_TOGGLE if PREEMPTION

	select GENERIC_TRACER

	default n

	help
@@ -214,7 +214,7 @@ config PREEMPT_TRACER 
	bool "Preemption-off Latency Tracer"

	default n

	depends on !ARCH_USES_GETTIMEOFFSET

	depends on PREEMPT

	depends on PREEMPTION

	select GENERIC_TRACER

	select TRACER_MAX_TRACE

	select RING_BUFFER_ALLOW_SWAP

kernel/trace/ftrace.c

+1 −1
Original line number Diff line number Diff line
@@ -2814,7 +2814,7 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) 
		 * synchornize_rcu_tasks() will wait for those tasks to

		 * execute and either schedule voluntarily or enter user space.

		 */

		if (IS_ENABLED(CONFIG_PREEMPT))

		if (IS_ENABLED(CONFIG_PREEMPTION))

			synchronize_rcu_tasks();



 free_ops:

kernel/trace/ring_buffer_benchmark.c

+1 −1
Original line number Diff line number Diff line
@@ -267,7 +267,7 @@ static void ring_buffer_producer(void) 
		if (consumer && !(cnt % wakeup_interval))

			wake_up_process(consumer);



#ifndef CONFIG_PREEMPT

#ifndef CONFIG_PREEMPTION

		/*

		 * If we are a non preempt kernel, the 10 second run will

		 * stop everything while it runs. Instead, we will call

kernel/trace/trace_events.c

+2 −2
Original line number Diff line number Diff line
@@ -255,12 +255,12 @@ void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer, 
	local_save_flags(fbuffer->flags);

	fbuffer->pc = preempt_count();

	/*

	 * If CONFIG_PREEMPT is enabled, then the tracepoint itself disables

	 * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables

	 * preemption (adding one to the preempt_count). Since we are

	 * interested in the preempt_count at the time the tracepoint was

	 * hit, we need to subtract one to offset the increment.

	 */

	if (IS_ENABLED(CONFIG_PREEMPT))

	if (IS_ENABLED(CONFIG_PREEMPTION))

		fbuffer->pc--;

	fbuffer->trace_file = trace_file;

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