linux-imx

/**

 * @file cpu_buffer.c

 *

 * @remark Copyright 2002-2009 OProfile authors

 * @remark Read the file COPYING

 *

 * @author John Levon <levon@movementarian.org>

 * @author Barry Kasindorf <barry.kasindorf@amd.com>

 * @author Robert Richter <robert.richter@amd.com>

 *

 * Each CPU has a local buffer that stores PC value/event

 * pairs. We also log context switches when we notice them.

 * Eventually each CPU's buffer is processed into the global

 * event buffer by sync_buffer().

 *

 * We use a local buffer for two reasons: an NMI or similar

 * interrupt cannot synchronise, and high sampling rates

 * would lead to catastrophic global synchronisation if

 * a global buffer was used.

 */

​

#include <linux/sched.h>

#include <linux/oprofile.h>

#include <linux/errno.h>

​

#include <asm/ptrace.h>

​

#include "event_buffer.h"

#include "cpu_buffer.h"

#include "buffer_sync.h"

#include "oprof.h"

​

#define OP_BUFFER_FLAGS 0

​

static struct ring_buffer *op_ring_buffer;

DEFINE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer);

​

static void wq_sync_buffer(struct work_struct *work);

​

#define DEFAULT_TIMER_EXPIRE (HZ / 10)

static int work_enabled;

​

unsigned long oprofile_get_cpu_buffer_size(void)

{

    return oprofile_cpu_buffer_size;

}

​

void oprofile_cpu_buffer_inc_smpl_lost(void)

{

    struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);

​

    cpu_buf->sample_lost_overflow++;

}

​

void free_cpu_buffers(void)

{

    if (op_ring_buffer)

        ring_buffer_free(op_ring_buffer);

    op_ring_buffer = NULL;

}

​

#define RB_EVENT_HDR_SIZE 4

​