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 */