Linux 2.6.34-rc3
[pohmelfs.git] / drivers / oprofile / cpu_buffer.h
blob68ea16ab645f3e3e134b56db9269df2044234b92
1 /**
2 * @file cpu_buffer.h
4 * @remark Copyright 2002-2009 OProfile authors
5 * @remark Read the file COPYING
7 * @author John Levon <levon@movementarian.org>
8 * @author Robert Richter <robert.richter@amd.com>
9 */
11 #ifndef OPROFILE_CPU_BUFFER_H
12 #define OPROFILE_CPU_BUFFER_H
14 #include <linux/types.h>
15 #include <linux/spinlock.h>
16 #include <linux/workqueue.h>
17 #include <linux/cache.h>
18 #include <linux/sched.h>
19 #include <linux/ring_buffer.h>
21 struct task_struct;
23 int alloc_cpu_buffers(void);
24 void free_cpu_buffers(void);
26 void start_cpu_work(void);
27 void end_cpu_work(void);
29 /* CPU buffer is composed of such entries (which are
30 * also used for context switch notes)
32 struct op_sample {
33 unsigned long eip;
34 unsigned long event;
35 unsigned long data[0];
38 struct op_entry;
40 struct oprofile_cpu_buffer {
41 unsigned long buffer_size;
42 struct task_struct *last_task;
43 int last_is_kernel;
44 int tracing;
45 unsigned long sample_received;
46 unsigned long sample_lost_overflow;
47 unsigned long backtrace_aborted;
48 unsigned long sample_invalid_eip;
49 int cpu;
50 struct delayed_work work;
53 DECLARE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer);
56 * Resets the cpu buffer to a sane state.
58 * reset these to invalid values; the next sample collected will
59 * populate the buffer with proper values to initialize the buffer
61 static inline void op_cpu_buffer_reset(int cpu)
63 struct oprofile_cpu_buffer *cpu_buf = &per_cpu(op_cpu_buffer, cpu);
65 cpu_buf->last_is_kernel = -1;
66 cpu_buf->last_task = NULL;
70 * op_cpu_buffer_add_data() and op_cpu_buffer_write_commit() may be
71 * called only if op_cpu_buffer_write_reserve() did not return NULL or
72 * entry->event != NULL, otherwise entry->size or entry->event will be
73 * used uninitialized.
76 struct op_sample
77 *op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size);
78 int op_cpu_buffer_write_commit(struct op_entry *entry);
79 struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu);
80 unsigned long op_cpu_buffer_entries(int cpu);
82 /* returns the remaining free size of data in the entry */
83 static inline
84 int op_cpu_buffer_add_data(struct op_entry *entry, unsigned long val)
86 if (!entry->size)
87 return 0;
88 *entry->data = val;
89 entry->size--;
90 entry->data++;
91 return entry->size;
94 /* returns the size of data in the entry */
95 static inline
96 int op_cpu_buffer_get_size(struct op_entry *entry)
98 return entry->size;
101 /* returns 0 if empty or the size of data including the current value */
102 static inline
103 int op_cpu_buffer_get_data(struct op_entry *entry, unsigned long *val)
105 int size = entry->size;
106 if (!size)
107 return 0;
108 *val = *entry->data;
109 entry->size--;
110 entry->data++;
111 return size;
114 /* extra data flags */
115 #define KERNEL_CTX_SWITCH (1UL << 0)
116 #define IS_KERNEL (1UL << 1)
117 #define TRACE_BEGIN (1UL << 2)
118 #define USER_CTX_SWITCH (1UL << 3)
120 #endif /* OPROFILE_CPU_BUFFER_H */