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Commit 737223fb authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
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tracing: Consolidate buffer allocation code 



There's a bit of duplicate code in creating the trace buffers for
the normal trace buffer and the max trace buffer among the instances
and the main global_trace. This code can be consolidated and cleaned
up a bit making the code cleaner and more readable as well as less
duplication.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 45ad21ca

kernel/trace/trace.c

+63 −67
Original line number Diff line number Diff line
@@ -3171,6 +3171,7 @@ int tracer_init(struct tracer *t, struct trace_array *tr) 
static void set_buffer_entries(struct trace_buffer *buf, unsigned long val)

{

	int cpu;



	for_each_tracing_cpu(cpu)

		per_cpu_ptr(buf->data, cpu)->entries = val;

}
@@ -5267,12 +5268,70 @@ struct dentry *trace_instance_dir; 
static void

init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer);



static int new_instance_create(const char *name)

static void init_trace_buffers(struct trace_array *tr, struct trace_buffer *buf)

{

	int cpu;



	for_each_tracing_cpu(cpu) {

		memset(per_cpu_ptr(buf->data, cpu), 0, sizeof(struct trace_array_cpu));

		per_cpu_ptr(buf->data, cpu)->trace_cpu.cpu = cpu;

		per_cpu_ptr(buf->data, cpu)->trace_cpu.tr = tr;

	}

}



static int allocate_trace_buffers(struct trace_array *tr, int size)

{

	enum ring_buffer_flags rb_flags;



	rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;



	tr->trace_buffer.buffer = ring_buffer_alloc(size, rb_flags);

	if (!tr->trace_buffer.buffer)

		goto out_free;



	tr->trace_buffer.data = alloc_percpu(struct trace_array_cpu);

	if (!tr->trace_buffer.data)

		goto out_free;



	init_trace_buffers(tr, &tr->trace_buffer);



	/* Allocate the first page for all buffers */

	set_buffer_entries(&tr->trace_buffer,

			   ring_buffer_size(tr->trace_buffer.buffer, 0));



#ifdef CONFIG_TRACER_MAX_TRACE



	tr->max_buffer.buffer = ring_buffer_alloc(1, rb_flags);

	if (!tr->max_buffer.buffer)

		goto out_free;



	tr->max_buffer.data = alloc_percpu(struct trace_array_cpu);

	if (!tr->max_buffer.data)

		goto out_free;



	init_trace_buffers(tr, &tr->max_buffer);



	set_buffer_entries(&tr->max_buffer, 1);

#endif

	return 0;



 out_free:

	if (tr->trace_buffer.buffer)

		ring_buffer_free(tr->trace_buffer.buffer);

	free_percpu(tr->trace_buffer.data);



#ifdef CONFIG_TRACER_MAX_TRACE

	if (tr->max_buffer.buffer)

		ring_buffer_free(tr->max_buffer.buffer);

	free_percpu(tr->max_buffer.data);

#endif

	return -ENOMEM;

}



static int new_instance_create(const char *name)

{

	struct trace_array *tr;

	int ret;

	int i;



	mutex_lock(&trace_types_lock);
@@ -5298,22 +5357,9 @@ static int new_instance_create(const char *name) 
	INIT_LIST_HEAD(&tr->systems);

	INIT_LIST_HEAD(&tr->events);



	rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;



	tr->trace_buffer.buffer = ring_buffer_alloc(trace_buf_size, rb_flags);

	if (!tr->trace_buffer.buffer)

		goto out_free_tr;



	tr->trace_buffer.data = alloc_percpu(struct trace_array_cpu);

	if (!tr->trace_buffer.data)

	if (allocate_trace_buffers(tr, trace_buf_size) < 0)

		goto out_free_tr;



	for_each_tracing_cpu(i) {

		memset(per_cpu_ptr(tr->trace_buffer.data, i), 0, sizeof(struct trace_array_cpu));

		per_cpu_ptr(tr->trace_buffer.data, i)->trace_cpu.cpu = i;

		per_cpu_ptr(tr->trace_buffer.data, i)->trace_cpu.tr = tr;

	}



	/* Holder for file callbacks */

	tr->trace_cpu.cpu = RING_BUFFER_ALL_CPUS;

	tr->trace_cpu.tr = tr;
@@ -5736,8 +5782,6 @@ EXPORT_SYMBOL_GPL(ftrace_dump); 
__init static int tracer_alloc_buffers(void)

{

	int ring_buf_size;

	enum ring_buffer_flags rb_flags;

	int i;

	int ret = -ENOMEM;
@@ -5758,69 +5802,21 @@ __init static int tracer_alloc_buffers(void) 
	else

		ring_buf_size = 1;



	rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;



	cpumask_copy(tracing_buffer_mask, cpu_possible_mask);

	cpumask_copy(tracing_cpumask, cpu_all_mask);



	raw_spin_lock_init(&global_trace.start_lock);



	/* TODO: make the number of buffers hot pluggable with CPUS */

	global_trace.trace_buffer.buffer = ring_buffer_alloc(ring_buf_size, rb_flags);

	if (!global_trace.trace_buffer.buffer) {

	if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {

		printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");

		WARN_ON(1);

		goto out_free_cpumask;

	}



	global_trace.trace_buffer.data = alloc_percpu(struct trace_array_cpu);



	if (!global_trace.trace_buffer.data) {

		printk(KERN_ERR "tracer: failed to allocate percpu memory!\n");

		WARN_ON(1);

		goto out_free_cpumask;

	}



	for_each_tracing_cpu(i) {

		memset(per_cpu_ptr(global_trace.trace_buffer.data, i), 0,

		       sizeof(struct trace_array_cpu));

		per_cpu_ptr(global_trace.trace_buffer.data, i)->trace_cpu.cpu = i;

		per_cpu_ptr(global_trace.trace_buffer.data, i)->trace_cpu.tr = &global_trace;

	}



	if (global_trace.buffer_disabled)

		tracing_off();



#ifdef CONFIG_TRACER_MAX_TRACE

	global_trace.max_buffer.data = alloc_percpu(struct trace_array_cpu);

	if (!global_trace.max_buffer.data) {

		printk(KERN_ERR "tracer: failed to allocate percpu memory!\n");

		WARN_ON(1);

		goto out_free_cpumask;

	}

	global_trace.max_buffer.buffer = ring_buffer_alloc(1, rb_flags);

	if (!global_trace.max_buffer.buffer) {

		printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");

		WARN_ON(1);

		ring_buffer_free(global_trace.trace_buffer.buffer);

		goto out_free_cpumask;

	}



	for_each_tracing_cpu(i) {

		memset(per_cpu_ptr(global_trace.max_buffer.data, i), 0,

		       sizeof(struct trace_array_cpu));

		per_cpu_ptr(global_trace.max_buffer.data, i)->trace_cpu.cpu = i;

		per_cpu_ptr(global_trace.max_buffer.data, i)->trace_cpu.tr = &global_trace;

	}

#endif



	/* Allocate the first page for all buffers */

	set_buffer_entries(&global_trace.trace_buffer,

			   ring_buffer_size(global_trace.trace_buffer.buffer, 0));

#ifdef CONFIG_TRACER_MAX_TRACE

	set_buffer_entries(&global_trace.max_buffer, 1);

#endif



	trace_init_cmdlines();



	register_tracer(&nop_trace);