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Commit 5389f6fa authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
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locking, tracing: Annotate tracing locks as raw 



The tracing locks can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 740969f9

kernel/trace/ring_buffer.c

+26 −26
Original line number Diff line number Diff line
@@ -478,7 +478,7 @@ struct ring_buffer_per_cpu { 
	int				cpu;

	atomic_t			record_disabled;

	struct ring_buffer		*buffer;

	spinlock_t			reader_lock;	/* serialize readers */

	raw_spinlock_t			reader_lock;	/* serialize readers */

	arch_spinlock_t			lock;

	struct lock_class_key		lock_key;

	struct list_head		*pages;
@@ -1062,7 +1062,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) 


	cpu_buffer->cpu = cpu;

	cpu_buffer->buffer = buffer;

	spin_lock_init(&cpu_buffer->reader_lock);

	raw_spin_lock_init(&cpu_buffer->reader_lock);

	lockdep_set_class(&cpu_buffer->reader_lock, buffer->reader_lock_key);

	cpu_buffer->lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
@@ -1259,7 +1259,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) 
	struct list_head *p;

	unsigned i;



	spin_lock_irq(&cpu_buffer->reader_lock);

	raw_spin_lock_irq(&cpu_buffer->reader_lock);

	rb_head_page_deactivate(cpu_buffer);



	for (i = 0; i < nr_pages; i++) {
@@ -1277,7 +1277,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) 
	rb_check_pages(cpu_buffer);



out:

	spin_unlock_irq(&cpu_buffer->reader_lock);

	raw_spin_unlock_irq(&cpu_buffer->reader_lock);

}



static void
@@ -1288,7 +1288,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, 
	struct list_head *p;

	unsigned i;



	spin_lock_irq(&cpu_buffer->reader_lock);

	raw_spin_lock_irq(&cpu_buffer->reader_lock);

	rb_head_page_deactivate(cpu_buffer);



	for (i = 0; i < nr_pages; i++) {
@@ -1303,7 +1303,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, 
	rb_check_pages(cpu_buffer);



out:

	spin_unlock_irq(&cpu_buffer->reader_lock);

	raw_spin_unlock_irq(&cpu_buffer->reader_lock);

}



/**
@@ -2804,9 +2804,9 @@ void ring_buffer_iter_reset(struct ring_buffer_iter *iter) 


	cpu_buffer = iter->cpu_buffer;



	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	rb_iter_reset(iter);

	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

}

EXPORT_SYMBOL_GPL(ring_buffer_iter_reset);
@@ -3265,12 +3265,12 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts, 
 again:

	local_irq_save(flags);

	if (dolock)

		spin_lock(&cpu_buffer->reader_lock);

		raw_spin_lock(&cpu_buffer->reader_lock);

	event = rb_buffer_peek(cpu_buffer, ts, lost_events);

	if (event && event->type_len == RINGBUF_TYPE_PADDING)

		rb_advance_reader(cpu_buffer);

	if (dolock)

		spin_unlock(&cpu_buffer->reader_lock);

		raw_spin_unlock(&cpu_buffer->reader_lock);

	local_irq_restore(flags);



	if (event && event->type_len == RINGBUF_TYPE_PADDING)
@@ -3295,9 +3295,9 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts) 
	unsigned long flags;



 again:

	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	event = rb_iter_peek(iter, ts);

	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);



	if (event && event->type_len == RINGBUF_TYPE_PADDING)

		goto again;
@@ -3337,7 +3337,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, 
	cpu_buffer = buffer->buffers[cpu];

	local_irq_save(flags);

	if (dolock)

		spin_lock(&cpu_buffer->reader_lock);

		raw_spin_lock(&cpu_buffer->reader_lock);



	event = rb_buffer_peek(cpu_buffer, ts, lost_events);

	if (event) {
@@ -3346,7 +3346,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts, 
	}



	if (dolock)

		spin_unlock(&cpu_buffer->reader_lock);

		raw_spin_unlock(&cpu_buffer->reader_lock);

	local_irq_restore(flags);



 out:
@@ -3438,11 +3438,11 @@ ring_buffer_read_start(struct ring_buffer_iter *iter) 


	cpu_buffer = iter->cpu_buffer;



	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	arch_spin_lock(&cpu_buffer->lock);

	rb_iter_reset(iter);

	arch_spin_unlock(&cpu_buffer->lock);

	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

}

EXPORT_SYMBOL_GPL(ring_buffer_read_start);
@@ -3477,7 +3477,7 @@ ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts) 
	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;

	unsigned long flags;



	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

 again:

	event = rb_iter_peek(iter, ts);

	if (!event)
@@ -3488,7 +3488,7 @@ ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts) 


	rb_advance_iter(iter);

 out:

	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);



	return event;

}
@@ -3557,7 +3557,7 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu) 


	atomic_inc(&cpu_buffer->record_disabled);



	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);



	if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))

		goto out;
@@ -3569,7 +3569,7 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu) 
	arch_spin_unlock(&cpu_buffer->lock);



 out:

	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);



	atomic_dec(&cpu_buffer->record_disabled);

}
@@ -3607,10 +3607,10 @@ int ring_buffer_empty(struct ring_buffer *buffer) 
		cpu_buffer = buffer->buffers[cpu];

		local_irq_save(flags);

		if (dolock)

			spin_lock(&cpu_buffer->reader_lock);

			raw_spin_lock(&cpu_buffer->reader_lock);

		ret = rb_per_cpu_empty(cpu_buffer);

		if (dolock)

			spin_unlock(&cpu_buffer->reader_lock);

			raw_spin_unlock(&cpu_buffer->reader_lock);

		local_irq_restore(flags);



		if (!ret)
@@ -3641,10 +3641,10 @@ int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu) 
	cpu_buffer = buffer->buffers[cpu];

	local_irq_save(flags);

	if (dolock)

		spin_lock(&cpu_buffer->reader_lock);

		raw_spin_lock(&cpu_buffer->reader_lock);

	ret = rb_per_cpu_empty(cpu_buffer);

	if (dolock)

		spin_unlock(&cpu_buffer->reader_lock);

		raw_spin_unlock(&cpu_buffer->reader_lock);

	local_irq_restore(flags);



	return ret;
@@ -3841,7 +3841,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer, 
	if (!bpage)

		goto out;



	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);

	raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);



	reader = rb_get_reader_page(cpu_buffer);

	if (!reader)
@@ -3964,7 +3964,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer, 
		memset(&bpage->data[commit], 0, BUF_PAGE_SIZE - commit);



 out_unlock:

	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);

	raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);



 out:

	return ret;

kernel/trace/trace.c

+5 −5
Original line number Diff line number Diff line
@@ -341,7 +341,7 @@ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | 
	TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE;



static int trace_stop_count;

static DEFINE_SPINLOCK(tracing_start_lock);

static DEFINE_RAW_SPINLOCK(tracing_start_lock);



static void wakeup_work_handler(struct work_struct *work)

{
@@ -960,7 +960,7 @@ void tracing_start(void) 
	if (tracing_disabled)

		return;



	spin_lock_irqsave(&tracing_start_lock, flags);

	raw_spin_lock_irqsave(&tracing_start_lock, flags);

	if (--trace_stop_count) {

		if (trace_stop_count < 0) {

			/* Someone screwed up their debugging */
@@ -985,7 +985,7 @@ void tracing_start(void) 


	ftrace_start();

 out:

	spin_unlock_irqrestore(&tracing_start_lock, flags);

	raw_spin_unlock_irqrestore(&tracing_start_lock, flags);

}



/**
@@ -1000,7 +1000,7 @@ void tracing_stop(void) 
	unsigned long flags;



	ftrace_stop();

	spin_lock_irqsave(&tracing_start_lock, flags);

	raw_spin_lock_irqsave(&tracing_start_lock, flags);

	if (trace_stop_count++)

		goto out;
@@ -1018,7 +1018,7 @@ void tracing_stop(void) 
	arch_spin_unlock(&ftrace_max_lock);



 out:

	spin_unlock_irqrestore(&tracing_start_lock, flags);

	raw_spin_unlock_irqrestore(&tracing_start_lock, flags);

}



void trace_stop_cmdline_recording(void);

kernel/trace/trace_irqsoff.c

+3 −3
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ static int tracer_enabled __read_mostly; 


static DEFINE_PER_CPU(int, tracing_cpu);



static DEFINE_SPINLOCK(max_trace_lock);

static DEFINE_RAW_SPINLOCK(max_trace_lock);



enum {

	TRACER_IRQS_OFF		= (1 << 1),
@@ -321,7 +321,7 @@ check_critical_timing(struct trace_array *tr, 
	if (!report_latency(delta))

		goto out;



	spin_lock_irqsave(&max_trace_lock, flags);

	raw_spin_lock_irqsave(&max_trace_lock, flags);



	/* check if we are still the max latency */

	if (!report_latency(delta))
@@ -344,7 +344,7 @@ check_critical_timing(struct trace_array *tr, 
	max_sequence++;



out_unlock:

	spin_unlock_irqrestore(&max_trace_lock, flags);

	raw_spin_unlock_irqrestore(&max_trace_lock, flags);



out:

	data->critical_sequence = max_sequence;