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Commit 76369139 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
Browse files

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: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: default avatarPeter 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: default avatarIngo Molnar <mingo@elte.hu>
parent b58f6b0d

include/linux/perf_event.h

+4 −29
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

kernel/events/core.c

+71 −497

File changed.

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kernel/events/internal.h

0 → 100644
+97 −0
Original line number Diff line number Diff line 
#ifndef _KERNEL_EVENTS_INTERNAL_H

#define _KERNEL_EVENTS_INTERNAL_H



#define RING_BUFFER_WRITABLE		0x01



struct ring_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];

};





extern void rb_free(struct ring_buffer *rb);

extern struct ring_buffer *

rb_alloc(int nr_pages, long watermark, int cpu, int flags);

extern void perf_event_wakeup(struct perf_event *event);



extern void

perf_event_header__init_id(struct perf_event_header *header,

			   struct perf_sample_data *data,

			   struct perf_event *event);

extern void

perf_event__output_id_sample(struct perf_event *event,

			     struct perf_output_handle *handle,

			     struct perf_sample_data *sample);



extern struct page *

perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);



#ifdef CONFIG_PERF_USE_VMALLOC

/*

 * Back perf_mmap() with vmalloc memory.

 *

 * Required for architectures that have d-cache aliasing issues.

 */



static inline int page_order(struct ring_buffer *rb)

{

	return rb->page_order;

}



#else



static inline int page_order(struct ring_buffer *rb)

{

	return 0;

}

#endif



static unsigned long perf_data_size(struct ring_buffer *rb)

{

	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));

}



static inline void

__output_copy(struct perf_output_handle *handle,

		   const void *buf, unsigned int len)

{

	do {

		unsigned long size = min_t(unsigned long, handle->size, len);



		memcpy(handle->addr, buf, size);



		len -= size;

		handle->addr += size;

		buf += size;

		handle->size -= size;

		if (!handle->size) {

			struct ring_buffer *rb = handle->rb;



			handle->page++;

			handle->page &= rb->nr_pages - 1;

			handle->addr = rb->data_pages[handle->page];

			handle->size = PAGE_SIZE << page_order(rb);

		}

	} while (len);

}



#endif /* _KERNEL_EVENTS_INTERNAL_H */

kernel/events/ring_buffer.c

0 → 100644
+399 −0

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