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         spinlock_t              lock;
  59         cycle_t                 time_offset;
  60
  61         /* these fields get copied into max-trace: */
  62         unsigned                trace_head_idx;
  63         unsigned                trace_tail_idx;
  64         void                    *trace_head; /* producer */
  65         void                    *trace_tail; /* consumer */
  66         unsigned long           trace_idx;
  67         unsigned long           saved_latency;
  68         unsigned long           critical_start;
  69         unsigned long           critical_end;
  70         unsigned long           critical_sequence;
  71         unsigned long           nice;
  72         unsigned long           policy;
  73         unsigned long           rt_priority;
  74         cycle_t                 preempt_timestamp;
  75         pid_t                   pid;
  76         uid_t                   uid;
  77         char                    comm[TASK_COMM_LEN];
  78 };
  79
  80 struct trace_iterator;
  81
  82 /*
  83  * The trace array - an array of per-CPU trace arrays. This is the
  84  * highest level data structure that individual tracers deal with.
  85  * They have on/off state as well:
  86  */
  87 struct trace_array {
  88         unsigned long           entries;
  89         long                    ctrl;
  90         int                     cpu;
  91         cycle_t                 time_start;
  92         struct task_struct      *waiter;
  93         struct trace_array_cpu  *data[NR_CPUS];
  94 };
  95
  96 /*
  97  * A specific tracer, represented by methods that operate on a trace array:
  98  */
  99 struct tracer {
 100         const char              *name;
 101         void                    (*init)(struct trace_array *tr);
 102         void                    (*reset)(struct trace_array *tr);
 103         void                    (*open)(struct trace_iterator *iter);
 104         void                    (*close)(struct trace_iterator *iter);
 105         void                    (*start)(struct trace_iterator *iter);
 106         void                    (*stop)(struct trace_iterator *iter);
 107         void                    (*ctrl_update)(struct trace_array *tr);
 108 #ifdef CONFIG_FTRACE_STARTUP_TEST
 109         int                     (*selftest)(struct tracer *trace,
 110                                             struct trace_array *tr);
 111 #endif
 112         struct tracer           *next;
 113         int                     print_max;
 114 };
 115
 116 struct trace_seq {
 117         unsigned char           buffer[PAGE_SIZE];
 118         unsigned int            len;
 119 };
 120
 121 /*
 122  * Trace iterator - used by printout routines who present trace
 123  * results to users and which routines might sleep, etc:
 124  */
 125 struct trace_iterator {
 126         struct trace_seq        seq;
 127         struct trace_array      *tr;
 128         struct tracer           *trace;
 129
 130         struct trace_entry      *ent;
 131         int                     cpu;
 132
 133         struct trace_entry      *prev_ent;
 134         int                     prev_cpu;
 135
 136         unsigned long           iter_flags;
 137         loff_t                  pos;
 138         unsigned long           next_idx[NR_CPUS];
 139         struct list_head        *next_page[NR_CPUS];
 140         unsigned                next_page_idx[NR_CPUS];
 141         long                    idx;
 142 };
 143
 144 void notrace tracing_reset(struct trace_array_cpu *data);
 145 int tracing_open_generic(struct inode *inode, struct file *filp);
 146 struct dentry *tracing_init_dentry(void);
 147 void ftrace(struct trace_array *tr,
 148                             struct trace_array_cpu *data,
 149                             unsigned long ip,
 150                             unsigned long parent_ip,
 151                             unsigned long flags);
 152 void tracing_sched_switch_trace(struct trace_array *tr,
 153                                 struct trace_array_cpu *data,
 154                                 struct task_struct *prev,
 155                                 struct task_struct *next,
 156                                 unsigned long flags);
 157 void tracing_record_cmdline(struct task_struct *tsk);
 158
 159 void tracing_start_function_trace(void);
 160 void tracing_stop_function_trace(void);
 161 int register_tracer(struct tracer *type);
 162 void unregister_tracer(struct tracer *type);
 163
 164 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 165
 166 extern unsigned long tracing_max_latency;
 167 extern unsigned long tracing_thresh;
 168
 169 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 170 void update_max_tr_single(struct trace_array *tr,
 171                           struct task_struct *tsk, int cpu);
 172
 173 static inline notrace cycle_t now(int cpu)
 174 {
 175         return cpu_clock(cpu);
 176 }
 177
 178 #ifdef CONFIG_SCHED_TRACER
 179 extern void notrace
 180 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next);
 181 #else
 182 static inline void
 183 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
 184 {
 185 }
 186 #endif
 187
 188 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 189 typedef void
 190 (*tracer_switch_func_t)(void *private,
 191                         struct task_struct *prev,
 192                         struct task_struct *next);
 193
 194 struct tracer_switch_ops {
 195         tracer_switch_func_t            func;
 196         void                            *private;
 197         struct tracer_switch_ops        *next;
 198 };
 199
 200 extern int register_tracer_switch(struct tracer_switch_ops *ops);
 201 extern int unregister_tracer_switch(struct tracer_switch_ops *ops);
 202
 203 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 204
 205 #ifdef CONFIG_DYNAMIC_FTRACE
 206 extern unsigned long ftrace_update_tot_cnt;
 207 #endif
 208
 209 #ifdef CONFIG_FTRACE_STARTUP_TEST
 210 #ifdef CONFIG_FTRACE
 211 extern int trace_selftest_startup_function(struct tracer *trace,
 212                                            struct trace_array *tr);
 213 #endif
 214 #ifdef CONFIG_IRQSOFF_TRACER
 215 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 216                                           struct trace_array *tr);
 217 #endif
 218 #ifdef CONFIG_PREEMPT_TRACER
 219 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 220                                              struct trace_array *tr);
 221 #endif
 222 #if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 223 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 224                                                  struct trace_array *tr);
 225 #endif
 226 #ifdef CONFIG_SCHED_TRACER
 227 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 228                                          struct trace_array *tr);
 229 #endif
 230 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 231 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 232                                                struct trace_array *tr);
 233 #endif
 234 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 235
 236 extern void *head_page(struct trace_array_cpu *data);
 237
 238 #endif /* _LINUX_KERNEL_TRACE_H */