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         struct list_head        trace_pages;
  57         atomic_t                disabled;
  58         cycle_t                 time_offset;
  59
  60         /* these fields get copied into max-trace: */
  61         unsigned                trace_head_idx;
  62         unsigned                trace_tail_idx;
  63         void                    *trace_head; /* producer */
  64         void                    *trace_tail; /* consumer */
  65         unsigned long           trace_idx;
  66         unsigned long           saved_latency;
  67         unsigned long           critical_start;
  68         unsigned long           critical_end;
  69         unsigned long           critical_sequence;
  70         unsigned long           nice;
  71         unsigned long           policy;
  72         unsigned long           rt_priority;
  73         cycle_t                 preempt_timestamp;
  74         pid_t                   pid;
  75         uid_t                   uid;
  76         char                    comm[TASK_COMM_LEN];
  77 };
  78
  79 struct trace_iterator;
  80
  81 /*
  82  * The trace array - an array of per-CPU trace arrays. This is the
  83  * highest level data structure that individual tracers deal with.
  84  * They have on/off state as well:
  85  */
  86 struct trace_array {
  87         unsigned long           entries;
  88         long                    ctrl;
  89         int                     cpu;
  90         cycle_t                 time_start;
  91         struct trace_array_cpu  *data[NR_CPUS];
  92 };
  93
  94 /*
  95  * A specific tracer, represented by methods that operate on a trace array:
  96  */
  97 struct tracer {
  98         const char              *name;
  99         void                    (*init)(struct trace_array *tr);
 100         void                    (*reset)(struct trace_array *tr);
 101         void                    (*open)(struct trace_iterator *iter);
 102         void                    (*close)(struct trace_iterator *iter);
 103         void                    (*start)(struct trace_iterator *iter);
 104         void                    (*stop)(struct trace_iterator *iter);
 105         void                    (*ctrl_update)(struct trace_array *tr);
 106 #ifdef CONFIG_FTRACE_STARTUP_TEST
 107         int                     (*selftest)(struct tracer *trace,
 108                                             struct trace_array *tr);
 109 #endif
 110         struct tracer           *next;
 111         int                     print_max;
 112 };
 113
 114 struct trace_seq {
 115         unsigned char           buffer[PAGE_SIZE];
 116         unsigned int            len;
 117 };
 118
 119 /*
 120  * Trace iterator - used by printout routines who present trace
 121  * results to users and which routines might sleep, etc:
 122  */
 123 struct trace_iterator {
 124         struct trace_seq        seq;
 125         struct trace_array      *tr;
 126         struct tracer           *trace;
 127
 128         struct trace_entry      *ent;
 129         int                     cpu;
 130
 131         struct trace_entry      *prev_ent;
 132         int                     prev_cpu;
 133
 134         unsigned long           iter_flags;
 135         loff_t                  pos;
 136         unsigned long           next_idx[NR_CPUS];
 137         struct list_head        *next_page[NR_CPUS];
 138         unsigned                next_page_idx[NR_CPUS];
 139         long                    idx;
 140 };
 141
 142 void notrace tracing_reset(struct trace_array_cpu *data);
 143 int tracing_open_generic(struct inode *inode, struct file *filp);
 144 struct dentry *tracing_init_dentry(void);
 145 void ftrace(struct trace_array *tr,
 146                             struct trace_array_cpu *data,
 147                             unsigned long ip,
 148                             unsigned long parent_ip,
 149                             unsigned long flags);
 150 void tracing_sched_switch_trace(struct trace_array *tr,
 151                                 struct trace_array_cpu *data,
 152                                 struct task_struct *prev,
 153                                 struct task_struct *next,
 154                                 unsigned long flags);
 155 void tracing_record_cmdline(struct task_struct *tsk);
 156
 157 void tracing_start_function_trace(void);
 158 void tracing_stop_function_trace(void);
 159 int register_tracer(struct tracer *type);
 160 void unregister_tracer(struct tracer *type);
 161
 162 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 163
 164 extern unsigned long tracing_max_latency;
 165 extern unsigned long tracing_thresh;
 166
 167 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 168 void update_max_tr_single(struct trace_array *tr,
 169                           struct task_struct *tsk, int cpu);
 170
 171 static inline notrace cycle_t now(int cpu)
 172 {
 173         return cpu_clock(cpu);
 174 }
 175
 176 #ifdef CONFIG_SCHED_TRACER
 177 extern void notrace
 178 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next);
 179 #else
 180 static inline void
 181 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
 182 {
 183 }
 184 #endif
 185
 186 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 187 typedef void
 188 (*tracer_switch_func_t)(void *private,
 189                         struct task_struct *prev,
 190                         struct task_struct *next);
 191
 192 struct tracer_switch_ops {
 193         tracer_switch_func_t            func;
 194         void                            *private;
 195         struct tracer_switch_ops        *next;
 196 };
 197
 198 extern int register_tracer_switch(struct tracer_switch_ops *ops);
 199 extern int unregister_tracer_switch(struct tracer_switch_ops *ops);
 200
 201 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 202
 203 #ifdef CONFIG_DYNAMIC_FTRACE
 204 extern unsigned long ftrace_update_tot_cnt;
 205 #endif
 206
 207 #ifdef CONFIG_FTRACE_STARTUP_TEST
 208 #ifdef CONFIG_FTRACE
 209 extern int trace_selftest_startup_function(struct tracer *trace,
 210                                            struct trace_array *tr);
 211 #endif
 212 #ifdef CONFIG_IRQSOFF_TRACER
 213 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 214                                           struct trace_array *tr);
 215 #endif
 216 #ifdef CONFIG_PREEMPT_TRACER
 217 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 218                                              struct trace_array *tr);
 219 #endif
 220 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 221 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 222                                                  struct trace_array *tr);
 223 #endif
 224 #ifdef CONFIG_SCHED_TRACER
 225 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 226                                          struct trace_array *tr);
 227 #endif
 228 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 229 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 230                                                struct trace_array *tr);
 231 #endif
 232 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 233
 234 extern void *head_page(struct trace_array_cpu *data);
 235
 236 #endif /* _LINUX_KERNEL_TRACE_H */