perf: Split up buffer handling from core code

And create the internal perf events header.

v2: Keep an internal inlined perf_output_copy()

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1305827704-5607-1-git-send-email-fweisbec@gmail.com
[ v3: use clearer 'ring_buffer' and 'rb' naming ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/perf_event.h

@@ -680,33 +680,6 @@ enum perf_event_active_state {
 };
 
 struct file;
-
-#define PERF_BUFFER_WRITABLE		0x01
-
-struct perf_buffer {
-	atomic_t			refcount;
-	struct rcu_head			rcu_head;
-#ifdef CONFIG_PERF_USE_VMALLOC
-	struct work_struct		work;
-	int				page_order;	/* allocation order  */
-#endif
-	int				nr_pages;	/* nr of data pages  */
-	int				writable;	/* are we writable   */
-
-	atomic_t			poll;		/* POLL_ for wakeups */
-
-	local_t				head;		/* write position    */
-	local_t				nest;		/* nested writers    */
-	local_t				events;		/* event limit       */
-	local_t				wakeup;		/* wakeup stamp      */
-	local_t				lost;		/* nr records lost   */
-
-	long				watermark;	/* wakeup watermark  */
-
-	struct perf_event_mmap_page	*user_page;
-	void				*data_pages[0];
-};
-
 struct perf_sample_data;
 
 typedef void (*perf_overflow_handler_t)(struct perf_event *, int,
@@ -745,6 +718,8 @@ struct perf_cgroup {
 };
 #endif
 
+struct ring_buffer;
+
 /**
  * struct perf_event - performance event kernel representation:
  */
@@ -834,7 +809,7 @@ struct perf_event {
 	atomic_t			mmap_count;
 	int				mmap_locked;
 	struct user_struct		*mmap_user;
-	struct perf_buffer		*buffer;
+	struct ring_buffer		*rb;
 
 	/* poll related */
 	wait_queue_head_t		waitq;
@@ -945,7 +920,7 @@ struct perf_cpu_context {
 
 struct perf_output_handle {
 	struct perf_event		*event;
-	struct perf_buffer		*buffer;
+	struct ring_buffer		*rb;
 	unsigned long			wakeup;
 	unsigned long			size;
 	void				*addr;

kernel/events/Makefile

@@ -2,5 +2,5 @@ ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_core.o = -pg
 endif
 
-obj-y := core.o
+obj-y := core.o ring_buffer.o
 obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o