ftrace: function tracer
[safe/jmp/linux-2.6] / kernel / trace / trace.h
1 #ifndef _LINUX_KERNEL_TRACE_H
2 #define _LINUX_KERNEL_TRACE_H
3
4 #include <linux/fs.h>
5 #include <asm/atomic.h>
6 #include <linux/sched.h>
7 #include <linux/clocksource.h>
8
9 /*
10  * Function trace entry - function address and parent function addres:
11  */
12 struct ftrace_entry {
13         unsigned long           ip;
14         unsigned long           parent_ip;
15 };
16
17 /*
18  * Context switch trace entry - which task (and prio) we switched from/to:
19  */
20 struct ctx_switch_entry {
21         unsigned int            prev_pid;
22         unsigned char           prev_prio;
23         unsigned char           prev_state;
24         unsigned int            next_pid;
25         unsigned char           next_prio;
26 };
27
28 /*
29  * The trace entry - the most basic unit of tracing. This is what
30  * is printed in the end as a single line in the trace output, such as:
31  *
32  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
33  */
34 struct trace_entry {
35         char                    type;
36         char                    cpu;
37         char                    flags;
38         char                    preempt_count;
39         int                     pid;
40         cycle_t                 t;
41         unsigned long           idx;
42         union {
43                 struct ftrace_entry             fn;
44                 struct ctx_switch_entry         ctx;
45         };
46 };
47
48 #define TRACE_ENTRY_SIZE        sizeof(struct trace_entry)
49
50 /*
51  * The CPU trace array - it consists of thousands of trace entries
52  * plus some other descriptor data: (for example which task started
53  * the trace, etc.)
54  */
55 struct trace_array_cpu {
56         void                    *trace;
57         unsigned long           trace_idx;
58         atomic_t                disabled;
59         atomic_t                underrun;
60         unsigned long           saved_latency;
61         unsigned long           critical_start;
62         unsigned long           critical_end;
63         unsigned long           critical_sequence;
64         unsigned long           nice;
65         unsigned long           policy;
66         unsigned long           rt_priority;
67         cycle_t                 preempt_timestamp;
68         pid_t                   pid;
69         uid_t                   uid;
70         char                    comm[TASK_COMM_LEN];
71 };
72
73 struct trace_iterator;
74
75 /*
76  * The trace array - an array of per-CPU trace arrays. This is the
77  * highest level data structure that individual tracers deal with.
78  * They have on/off state as well:
79  */
80 struct trace_array {
81         unsigned long           entries;
82         long                    ctrl;
83         int                     cpu;
84         cycle_t                 time_start;
85         struct trace_array_cpu  *data[NR_CPUS];
86 };
87
88 /*
89  * A specific tracer, represented by methods that operate on a trace array:
90  */
91 struct tracer {
92         const char              *name;
93         void                    (*init)(struct trace_array *tr);
94         void                    (*reset)(struct trace_array *tr);
95         void                    (*open)(struct trace_iterator *iter);
96         void                    (*close)(struct trace_iterator *iter);
97         void                    (*start)(struct trace_iterator *iter);
98         void                    (*stop)(struct trace_iterator *iter);
99         void                    (*ctrl_update)(struct trace_array *tr);
100         struct tracer           *next;
101         int                     print_max;
102 };
103
104 /*
105  * Trace iterator - used by printout routines who present trace
106  * results to users and which routines might sleep, etc:
107  */
108 struct trace_iterator {
109         struct trace_array      *tr;
110         struct tracer           *trace;
111         struct trace_entry      *ent;
112         unsigned long           iter_flags;
113         loff_t                  pos;
114         unsigned long           next_idx[NR_CPUS];
115         int                     cpu;
116         int                     idx;
117 };
118
119 void notrace tracing_reset(struct trace_array_cpu *data);
120 int tracing_open_generic(struct inode *inode, struct file *filp);
121 struct dentry *tracing_init_dentry(void);
122 void ftrace(struct trace_array *tr,
123                             struct trace_array_cpu *data,
124                             unsigned long ip,
125                             unsigned long parent_ip,
126                             unsigned long flags);
127 void tracing_sched_switch_trace(struct trace_array *tr,
128                                 struct trace_array_cpu *data,
129                                 struct task_struct *prev,
130                                 struct task_struct *next,
131                                 unsigned long flags);
132 void tracing_record_cmdline(struct task_struct *tsk);
133
134 void tracing_start_function_trace(void);
135 void tracing_stop_function_trace(void);
136 int register_tracer(struct tracer *type);
137 void unregister_tracer(struct tracer *type);
138
139 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
140
141 extern unsigned long tracing_max_latency;
142 extern unsigned long tracing_thresh;
143
144 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
145 void update_max_tr_single(struct trace_array *tr,
146                           struct task_struct *tsk, int cpu);
147
148 static inline notrace cycle_t now(int cpu)
149 {
150         return cpu_clock(cpu);
151 }
152
153 #ifdef CONFIG_SCHED_TRACER
154 extern void notrace
155 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next);
156 #else
157 static inline void
158 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
159 {
160 }
161 #endif
162
163 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
164 typedef void
165 (*tracer_switch_func_t)(void *private,
166                         struct task_struct *prev,
167                         struct task_struct *next);
168
169 struct tracer_switch_ops {
170         tracer_switch_func_t            func;
171         void                            *private;
172         struct tracer_switch_ops        *next;
173 };
174
175 extern int register_tracer_switch(struct tracer_switch_ops *ops);
176 extern int unregister_tracer_switch(struct tracer_switch_ops *ops);
177
178 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
179
180 #ifdef CONFIG_DYNAMIC_FTRACE
181 extern unsigned long ftrace_update_tot_cnt;
182 #endif
183
184 #endif /* _LINUX_KERNEL_TRACE_H */