Commit 9c01fe45 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Steven Rostedt
Browse files

tracing: Kill trace_cpu struct/members 

After the previous changes trace_array_cpu->trace_cpu and
trace_array->trace_cpu becomes write-only. Remove these members
and kill "struct trace_cpu" as well.

As a side effect this also removes memset(per_cpu_memory, 0).
It was not needed, alloc_percpu() returns zero-filled memory.

Link: http://lkml.kernel.org/r/20130723152613.GA23741@redhat.com



Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 6484c71c

kernel/trace/trace.c

+0 −21
Original line number Diff line number Diff line
@@ -5865,17 +5865,6 @@ struct dentry *trace_instance_dir; 
static void

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



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_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)

{
@@ -5893,8 +5882,6 @@ allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size 
		return -ENOMEM;

	}



	init_trace_buffers(tr, buf);



	/* Allocate the first page for all buffers */

	set_buffer_entries(&tr->trace_buffer,

			   ring_buffer_size(tr->trace_buffer.buffer, 0));
@@ -5961,10 +5948,6 @@ static int new_instance_create(const char *name) 
	if (allocate_trace_buffers(tr, trace_buf_size) < 0)

		goto out_free_tr;



	/* Holder for file callbacks */

	tr->trace_cpu.cpu = RING_BUFFER_ALL_CPUS;

	tr->trace_cpu.tr = tr;



	tr->dir = debugfs_create_dir(name, trace_instance_dir);

	if (!tr->dir)

		goto out_free_tr;
@@ -6438,10 +6421,6 @@ __init static int tracer_alloc_buffers(void) 


	global_trace.flags = TRACE_ARRAY_FL_GLOBAL;



	/* Holder for file callbacks */

	global_trace.trace_cpu.cpu = RING_BUFFER_ALL_CPUS;

	global_trace.trace_cpu.tr = &global_trace;



	INIT_LIST_HEAD(&global_trace.systems);

	INIT_LIST_HEAD(&global_trace.events);

	list_add(&global_trace.list, &ftrace_trace_arrays);

kernel/trace/trace.h

+0 −8
Original line number Diff line number Diff line
@@ -130,19 +130,12 @@ enum trace_flag_type { 


struct trace_array;



struct trace_cpu {

	struct trace_array	*tr;

	struct dentry		*dir;

	int			cpu;

};



/*

 * The CPU trace array - it consists of thousands of trace entries

 * plus some other descriptor data: (for example which task started

 * the trace, etc.)

 */

struct trace_array_cpu {

	struct trace_cpu	trace_cpu;

	atomic_t		disabled;

	void			*buffer_page;	/* ring buffer spare */
@@ -196,7 +189,6 @@ struct trace_array { 
	bool			allocated_snapshot;

#endif

	int			buffer_disabled;

	struct trace_cpu	trace_cpu;	/* place holder */

#ifdef CONFIG_FTRACE_SYSCALLS

	int			sys_refcount_enter;

	int			sys_refcount_exit;

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