oprofile: adding cpu_buffer_entries() (bf589e32) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/oprofile/buffer_sync.c

+2 −29

Original line number	Original line	Diff line number	Diff line
	@@ -464,33 +464,6 @@ static inline int is_code(unsigned long val)
	}		}


	/* "acquire" as many cpu buffer slots as we can */
	static unsigned long get_slots(struct oprofile_cpu_buffer *b)
	{
	unsigned long head = b->head_pos;
	unsigned long tail = b->tail_pos;

	/*
	* Subtle. This resets the persistent last_task
	* and in_kernel values used for switching notes.
	* BUT, there is a small window between reading
	* head_pos, and this call, that means samples
	* can appear at the new head position, but not
	* be prefixed with the notes for switching
	* kernel mode or a task switch. This small hole
	* can lead to mis-attribution or samples where
	* we don't know if it's in the kernel or not,
	* at the start of an event buffer.
	*/
	cpu_buffer_reset(b);

	if (head >= tail)
	return head - tail;

	return head + (b->buffer_size - tail);
	}


	/* Move tasks along towards death. Any tasks on dead_tasks		/* Move tasks along towards death. Any tasks on dead_tasks
	* will definitely have no remaining references in any		* will definitely have no remaining references in any
	* CPU buffers at this point, because we use two lists,		* CPU buffers at this point, because we use two lists,
	@@ -576,11 +549,11 @@ void sync_buffer(int cpu)
	/* Remember, only we can modify tail_pos */		/* Remember, only we can modify tail_pos */

	#ifndef CONFIG_OPROFILE_IBS		#ifndef CONFIG_OPROFILE_IBS
	available = get_slots(cpu_buf);		available = cpu_buffer_entries(cpu_buf);

	for (i = 0; i < available; ++i) {		for (i = 0; i < available; ++i) {
	#else		#else
	while (get_slots(cpu_buf)) {		while (cpu_buffer_entries(cpu_buf)) {
	#endif		#endif
	struct op_sample *s = cpu_buffer_read_entry(cpu_buf);		struct op_sample *s = cpu_buffer_read_entry(cpu_buf);

drivers/oprofile/cpu_buffer.h

+27 −0

Original line number	Original line	Diff line number	Diff line
	@@ -81,6 +81,33 @@ struct op_sample cpu_buffer_read_entry(struct oprofile_cpu_buffer cpu_buf)
	return &cpu_buf->buffer[cpu_buf->tail_pos];		return &cpu_buf->buffer[cpu_buf->tail_pos];
	}		}

			/* "acquire" as many cpu buffer slots as we can */
			static inline
			unsigned long cpu_buffer_entries(struct oprofile_cpu_buffer *b)
			{
			unsigned long head = b->head_pos;
			unsigned long tail = b->tail_pos;

			/*
			* Subtle. This resets the persistent last_task
			* and in_kernel values used for switching notes.
			* BUT, there is a small window between reading
			* head_pos, and this call, that means samples
			* can appear at the new head position, but not
			* be prefixed with the notes for switching
			* kernel mode or a task switch. This small hole
			* can lead to mis-attribution or samples where
			* we don't know if it's in the kernel or not,
			* at the start of an event buffer.
			*/
			cpu_buffer_reset(b);

			if (head >= tail)
			return head - tail;

			return head + (b->buffer_size - tail);
			}

	/* transient events for the CPU buffer -> event buffer */		/* transient events for the CPU buffer -> event buffer */
	#define CPU_IS_KERNEL 1		#define CPU_IS_KERNEL 1
	#define CPU_TRACE_BEGIN 2		#define CPU_TRACE_BEGIN 2