drivers/oprofile/cpu_buffer.h

   1 /**
   2  * @file cpu_buffer.h
   3  *
   4  * @remark Copyright 2002 OProfile authors
   5  * @remark Read the file COPYING
   6  *
   7  * @author John Levon <levon@movementarian.org>
   8  */
   9
  10 #ifndef OPROFILE_CPU_BUFFER_H
  11 #define OPROFILE_CPU_BUFFER_H
  12
  13 #include <linux/types.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/cache.h>
  16
  17 struct task_struct;
  18
  19 /* allocate a sample buffer for each CPU */
  20 int alloc_cpu_buffers(void);
  21
  22 void free_cpu_buffers(void);
  23
  24 /* CPU buffer is composed of such entries (which are
  25  * also used for context switch notes)
  26  */
  27 struct op_sample {
  28         unsigned long eip;
  29         unsigned long event;
  30 };
  31
  32 struct oprofile_cpu_buffer {
  33         volatile unsigned long head_pos;
  34         volatile unsigned long tail_pos;
  35         unsigned long buffer_size;
  36         struct task_struct * last_task;
  37         int last_is_kernel;
  38         struct op_sample * buffer;
  39         unsigned long sample_received;
  40         unsigned long sample_lost_overflow;
  41         unsigned long sample_lost_task_exit;
  42 } ____cacheline_aligned;
  43
  44 extern struct oprofile_cpu_buffer cpu_buffer[];
  45
  46 void cpu_buffer_reset(struct oprofile_cpu_buffer *cpu_buf);
  47
  48 #endif /* OPROFILE_CPU_BUFFER_H */