 e6dab5ffab
			
		
	
	
	e6dab5ffab
	
	
	
		
			
			A few events are interesting not only for a current task. For example, sched_stat_* events are interesting for a task which wakes up. For this reason, it will be good if such events will be delivered to a target task too. Now a target task can be set by using __perf_task(). The original idea and a draft patch belongs to Peter Zijlstra. I need these events for profiling sleep times. sched_switch is used for getting callchains and sched_stat_* is used for getting time periods. These events are combined in user space, then it can be analyzed by perf tools. Inspired-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arun Sharma <asharma@fb.com> Signed-off-by: Andrew Vagin <avagin@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1342016098-213063-1-git-send-email-avagin@openvz.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
		
			
				
	
	
		
			137 lines
		
	
	
	
		
			3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			137 lines
		
	
	
	
		
			3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _KERNEL_EVENTS_INTERNAL_H
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| #define _KERNEL_EVENTS_INTERNAL_H
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| 
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| #include <linux/hardirq.h>
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| 
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| /* Buffer handling */
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| 
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| #define RING_BUFFER_WRITABLE		0x01
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| 
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| struct ring_buffer {
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| 	atomic_t			refcount;
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| 	struct rcu_head			rcu_head;
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| #ifdef CONFIG_PERF_USE_VMALLOC
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| 	struct work_struct		work;
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| 	int				page_order;	/* allocation order  */
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| #endif
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| 	int				nr_pages;	/* nr of data pages  */
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| 	int				writable;	/* are we writable   */
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| 
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| 	atomic_t			poll;		/* POLL_ for wakeups */
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| 
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| 	local_t				head;		/* write position    */
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| 	local_t				nest;		/* nested writers    */
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| 	local_t				events;		/* event limit       */
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| 	local_t				wakeup;		/* wakeup stamp      */
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| 	local_t				lost;		/* nr records lost   */
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| 
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| 	long				watermark;	/* wakeup watermark  */
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| 	/* poll crap */
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| 	spinlock_t			event_lock;
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| 	struct list_head		event_list;
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| 
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| 	struct perf_event_mmap_page	*user_page;
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| 	void				*data_pages[0];
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| };
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| 
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| extern void rb_free(struct ring_buffer *rb);
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| extern struct ring_buffer *
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| rb_alloc(int nr_pages, long watermark, int cpu, int flags);
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| extern void perf_event_wakeup(struct perf_event *event);
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| 
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| extern void
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| perf_event_header__init_id(struct perf_event_header *header,
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| 			   struct perf_sample_data *data,
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| 			   struct perf_event *event);
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| extern void
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| perf_event__output_id_sample(struct perf_event *event,
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| 			     struct perf_output_handle *handle,
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| 			     struct perf_sample_data *sample);
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| 
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| extern struct page *
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| perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
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| 
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| #ifdef CONFIG_PERF_USE_VMALLOC
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| /*
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|  * Back perf_mmap() with vmalloc memory.
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|  *
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|  * Required for architectures that have d-cache aliasing issues.
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|  */
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| 
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| static inline int page_order(struct ring_buffer *rb)
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| {
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| 	return rb->page_order;
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| }
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| 
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| #else
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| 
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| static inline int page_order(struct ring_buffer *rb)
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| {
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| 	return 0;
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| }
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| #endif
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| 
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| static inline unsigned long perf_data_size(struct ring_buffer *rb)
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| {
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| 	return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
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| }
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| 
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| static inline void
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| __output_copy(struct perf_output_handle *handle,
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| 		   const void *buf, unsigned int len)
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| {
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| 	do {
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| 		unsigned long size = min_t(unsigned long, handle->size, len);
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| 
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| 		memcpy(handle->addr, buf, size);
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| 
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| 		len -= size;
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| 		handle->addr += size;
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| 		buf += size;
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| 		handle->size -= size;
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| 		if (!handle->size) {
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| 			struct ring_buffer *rb = handle->rb;
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| 
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| 			handle->page++;
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| 			handle->page &= rb->nr_pages - 1;
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| 			handle->addr = rb->data_pages[handle->page];
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| 			handle->size = PAGE_SIZE << page_order(rb);
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| 		}
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| 	} while (len);
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| }
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| 
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| /* Callchain handling */
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| extern struct perf_callchain_entry *
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| perf_callchain(struct perf_event *event, struct pt_regs *regs);
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| extern int get_callchain_buffers(void);
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| extern void put_callchain_buffers(void);
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| 
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| static inline int get_recursion_context(int *recursion)
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| {
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| 	int rctx;
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| 
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| 	if (in_nmi())
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| 		rctx = 3;
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| 	else if (in_irq())
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| 		rctx = 2;
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| 	else if (in_softirq())
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| 		rctx = 1;
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| 	else
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| 		rctx = 0;
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| 
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| 	if (recursion[rctx])
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| 		return -1;
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| 
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| 	recursion[rctx]++;
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| 	barrier();
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| 
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| 	return rctx;
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| }
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| 
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| static inline void put_recursion_context(int *recursion, int rctx)
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| {
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| 	barrier();
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| 	recursion[rctx]--;
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| }
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| 
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| #endif /* _KERNEL_EVENTS_INTERNAL_H */
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