linux/drivers/oprofile/cpu_buffer.h
Robert Richter 2cc28b9f26 oprofile: add op_cpu_buffer_write_reserve()
This function prepares the cpu buffer to write a sample.

Struct op_entry is used during operations on the ring buffer while
struct op_sample contains the data that is stored in the ring
buffer. Struct entry can be uninitialized. The function reserves a
data array that is specified by size. Use op_cpu_buffer_write_commit()
after preparing the sample. In case of errors a null pointer is
returned, otherwise the pointer to the sample.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:37:44 +01:00

88 lines
2.0 KiB
C

/**
* @file cpu_buffer.h
*
* @remark Copyright 2002-2009 OProfile authors
* @remark Read the file COPYING
*
* @author John Levon <levon@movementarian.org>
* @author Robert Richter <robert.richter@amd.com>
*/
#ifndef OPROFILE_CPU_BUFFER_H
#define OPROFILE_CPU_BUFFER_H
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/cache.h>
#include <linux/sched.h>
#include <linux/ring_buffer.h>
struct task_struct;
int alloc_cpu_buffers(void);
void free_cpu_buffers(void);
void start_cpu_work(void);
void end_cpu_work(void);
/* CPU buffer is composed of such entries (which are
* also used for context switch notes)
*/
struct op_sample {
unsigned long eip;
unsigned long event;
unsigned long data[0];
};
struct op_entry {
struct ring_buffer_event *event;
struct op_sample *sample;
unsigned long irq_flags;
unsigned long size;
unsigned long *data;
};
struct oprofile_cpu_buffer {
unsigned long buffer_size;
struct task_struct *last_task;
int last_is_kernel;
int tracing;
unsigned long sample_received;
unsigned long sample_lost_overflow;
unsigned long backtrace_aborted;
unsigned long sample_invalid_eip;
int cpu;
struct delayed_work work;
};
DECLARE_PER_CPU(struct oprofile_cpu_buffer, cpu_buffer);
/*
* Resets the cpu buffer to a sane state.
*
* reset these to invalid values; the next sample collected will
* populate the buffer with proper values to initialize the buffer
*/
static inline void op_cpu_buffer_reset(int cpu)
{
struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu);
cpu_buf->last_is_kernel = -1;
cpu_buf->last_task = NULL;
}
struct op_sample
*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size);
int op_cpu_buffer_write_commit(struct op_entry *entry);
struct op_sample *op_cpu_buffer_read_entry(int cpu);
unsigned long op_cpu_buffer_entries(int cpu);
/* transient events for the CPU buffer -> event buffer */
#define CPU_IS_KERNEL 1
#define CPU_TRACE_BEGIN 2
#define IBS_FETCH_BEGIN 3
#define IBS_OP_BEGIN 4
#endif /* OPROFILE_CPU_BUFFER_H */