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  * Special (free-form) trace entry:
  30  */
  31 struct special_entry {
  32         unsigned long           arg1;
  33         unsigned long           arg2;
  34         unsigned long           arg3;
  35 };
  36
  37 /*
  38  * Stack-trace entry:
  39  */
  40
  41 #define FTRACE_STACK_ENTRIES    5
  42
  43 struct stack_entry {
  44         unsigned long           caller[FTRACE_STACK_ENTRIES];
  45 };
  46
  47 /*
  48  * The trace entry - the most basic unit of tracing. This is what
  49  * is printed in the end as a single line in the trace output, such as:
  50  *
  51  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  52  */
  53 struct trace_entry {
  54         char                    type;
  55         char                    cpu;
  56         char                    flags;
  57         char                    preempt_count;
  58         int                     pid;
  59         cycle_t                 t;
  60         union {
  61                 struct ftrace_entry             fn;
  62                 struct ctx_switch_entry         ctx;
  63                 struct special_entry            special;
  64                 struct stack_entry              stack;
  65         };
  66 };
  67
  68 #define TRACE_ENTRY_SIZE        sizeof(struct trace_entry)
  69
  70 /*
  71  * The CPU trace array - it consists of thousands of trace entries
  72  * plus some other descriptor data: (for example which task started
  73  * the trace, etc.)
  74  */
  75 struct trace_array_cpu {
  76         struct list_head        trace_pages;
  77         atomic_t                disabled;
  78         spinlock_t              lock;
  79         struct lock_class_key   lock_key;
  80
  81         /* these fields get copied into max-trace: */
  82         unsigned                trace_head_idx;
  83         unsigned                trace_tail_idx;
  84         void                    *trace_head; /* producer */
  85         void                    *trace_tail; /* consumer */
  86         unsigned long           trace_idx;
  87         unsigned long           saved_latency;
  88         unsigned long           critical_start;
  89         unsigned long           critical_end;
  90         unsigned long           critical_sequence;
  91         unsigned long           nice;
  92         unsigned long           policy;
  93         unsigned long           rt_priority;
  94         cycle_t                 preempt_timestamp;
  95         pid_t                   pid;
  96         uid_t                   uid;
  97         char                    comm[TASK_COMM_LEN];
  98 };
  99
 100 struct trace_iterator;
 101
 102 /*
 103  * The trace array - an array of per-CPU trace arrays. This is the
 104  * highest level data structure that individual tracers deal with.
 105  * They have on/off state as well:
 106  */
 107 struct trace_array {
 108         unsigned long           entries;
 109         long                    ctrl;
 110         int                     cpu;
 111         cycle_t                 time_start;
 112         struct task_struct      *waiter;
 113         struct trace_array_cpu  *data[NR_CPUS];
 114 };
 115
 116 /*
 117  * A specific tracer, represented by methods that operate on a trace array:
 118  */
 119 struct tracer {
 120         const char              *name;
 121         void                    (*init)(struct trace_array *tr);
 122         void                    (*reset)(struct trace_array *tr);
 123         void                    (*open)(struct trace_iterator *iter);
 124         void                    (*close)(struct trace_iterator *iter);
 125         void                    (*start)(struct trace_iterator *iter);
 126         void                    (*stop)(struct trace_iterator *iter);
 127         void                    (*ctrl_update)(struct trace_array *tr);
 128 #ifdef CONFIG_FTRACE_STARTUP_TEST
 129         int                     (*selftest)(struct tracer *trace,
 130                                             struct trace_array *tr);
 131 #endif
 132         struct tracer           *next;
 133         int                     print_max;
 134 };
 135
 136 struct trace_seq {
 137         unsigned char           buffer[PAGE_SIZE];
 138         unsigned int            len;
 139 };
 140
 141 /*
 142  * Trace iterator - used by printout routines who present trace
 143  * results to users and which routines might sleep, etc:
 144  */
 145 struct trace_iterator {
 146         struct trace_seq        seq;
 147         struct trace_array      *tr;
 148         struct tracer           *trace;
 149
 150         struct trace_entry      *ent;
 151         int                     cpu;
 152
 153         struct trace_entry      *prev_ent;
 154         int                     prev_cpu;
 155
 156         unsigned long           iter_flags;
 157         loff_t                  pos;
 158         unsigned long           next_idx[NR_CPUS];
 159         struct list_head        *next_page[NR_CPUS];
 160         unsigned                next_page_idx[NR_CPUS];
 161         long                    idx;
 162 };
 163
 164 void tracing_reset(struct trace_array_cpu *data);
 165 int tracing_open_generic(struct inode *inode, struct file *filp);
 166 struct dentry *tracing_init_dentry(void);
 167 void ftrace(struct trace_array *tr,
 168                             struct trace_array_cpu *data,
 169                             unsigned long ip,
 170                             unsigned long parent_ip,
 171                             unsigned long flags);
 172 void tracing_sched_switch_trace(struct trace_array *tr,
 173                                 struct trace_array_cpu *data,
 174                                 struct task_struct *prev,
 175                                 struct task_struct *next,
 176                                 unsigned long flags);
 177 void tracing_record_cmdline(struct task_struct *tsk);
 178
 179 void tracing_sched_wakeup_trace(struct trace_array *tr,
 180                                 struct trace_array_cpu *data,
 181                                 struct task_struct *wakee,
 182                                 struct task_struct *cur,
 183                                 unsigned long flags);
 184 void trace_special(struct trace_array *tr,
 185                    struct trace_array_cpu *data,
 186                    unsigned long arg1,
 187                    unsigned long arg2,
 188                    unsigned long arg3);
 189 void trace_function(struct trace_array *tr,
 190                     struct trace_array_cpu *data,
 191                     unsigned long ip,
 192                     unsigned long parent_ip,
 193                     unsigned long flags);
 194
 195 void tracing_start_function_trace(void);
 196 void tracing_stop_function_trace(void);
 197 int register_tracer(struct tracer *type);
 198 void unregister_tracer(struct tracer *type);
 199
 200 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 201
 202 extern unsigned long tracing_max_latency;
 203 extern unsigned long tracing_thresh;
 204
 205 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 206 void update_max_tr_single(struct trace_array *tr,
 207                           struct task_struct *tsk, int cpu);
 208
 209 extern cycle_t ftrace_now(int cpu);
 210
 211 #ifdef CONFIG_SCHED_TRACER
 212 extern void
 213 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next);
 214 extern void
 215 wakeup_sched_wakeup(struct task_struct *wakee, struct task_struct *curr);
 216 #else
 217 static inline void
 218 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
 219 {
 220 }
 221 static inline void
 222 wakeup_sched_wakeup(struct task_struct *wakee, struct task_struct *curr)
 223 {
 224 }
 225 #endif
 226
 227 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 228 typedef void
 229 (*tracer_switch_func_t)(void *private,
 230                         struct task_struct *prev,
 231                         struct task_struct *next);
 232
 233 struct tracer_switch_ops {
 234         tracer_switch_func_t            func;
 235         void                            *private;
 236         struct tracer_switch_ops        *next;
 237 };
 238
 239 extern int register_tracer_switch(struct tracer_switch_ops *ops);
 240 extern int unregister_tracer_switch(struct tracer_switch_ops *ops);
 241
 242 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 243
 244 #ifdef CONFIG_DYNAMIC_FTRACE
 245 extern unsigned long ftrace_update_tot_cnt;
 246 #endif
 247
 248 #ifdef CONFIG_FTRACE_STARTUP_TEST
 249 #ifdef CONFIG_FTRACE
 250 extern int trace_selftest_startup_function(struct tracer *trace,
 251                                            struct trace_array *tr);
 252 #endif
 253 #ifdef CONFIG_IRQSOFF_TRACER
 254 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 255                                           struct trace_array *tr);
 256 #endif
 257 #ifdef CONFIG_PREEMPT_TRACER
 258 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 259                                              struct trace_array *tr);
 260 #endif
 261 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 262 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 263                                                  struct trace_array *tr);
 264 #endif
 265 #ifdef CONFIG_SCHED_TRACER
 266 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 267                                          struct trace_array *tr);
 268 #endif
 269 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 270 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 271                                                struct trace_array *tr);
 272 #endif
 273 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 274
 275 extern void *head_page(struct trace_array_cpu *data);
 276
 277 #endif /* _LINUX_KERNEL_TRACE_H */