libust/tracer.h

   1 /*
   2  * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
   3  * Copyright (C) 2009 Pierre-Marc Fournier
   4  *
   5  * This contains the definitions for the Linux Trace Toolkit tracer.
   6  *
   7  * Ported to userspace by Pierre-Marc Fournier.
   8  *
   9  * This file is released under the GPLv2.
  10  */
  11
  12 #ifndef _LTT_TRACER_H
  13 #define _LTT_TRACER_H
  14
  15 #include <sys/types.h>
  16 #include <stdarg.h>
  17 //#include "list.h"
  18 #include "kernelcompat.h"
  19 #include "buffer.h"
  20 #include "relay.h"
  21 #include "channels.h"
  22 #include "tracercore.h"
  23 #include "marker.h"
  24
  25 /* Number of bytes to log with a read/write event */
  26 #define LTT_LOG_RW_SIZE                 32L
  27
  28 /* Interval (in jiffies) at which the LTT per-CPU timer fires */
  29 #define LTT_PERCPU_TIMER_INTERVAL       1
  30
  31 #ifndef LTT_ARCH_TYPE
  32 #define LTT_ARCH_TYPE                   LTT_ARCH_TYPE_UNDEFINED
  33 #endif
  34
  35 #ifndef LTT_ARCH_VARIANT
  36 #define LTT_ARCH_VARIANT                LTT_ARCH_VARIANT_NONE
  37 #endif
  38
  39 struct ltt_active_marker;
  40
  41 /* Maximum number of callbacks per marker */
  42 #define LTT_NR_CALLBACKS        10
  43
  44 struct ltt_serialize_closure;
  45 struct ltt_probe_private_data;
  46
  47 /* Serialization callback '%k' */
  48 typedef size_t (*ltt_serialize_cb)(struct rchan_buf *buf, size_t buf_offset,
  49                         struct ltt_serialize_closure *closure,
  50                         void *serialize_private, int *largest_align,
  51                         const char *fmt, va_list *args);
  52
  53 struct ltt_serialize_closure {
  54         ltt_serialize_cb *callbacks;
  55         long cb_args[LTT_NR_CALLBACKS];
  56         unsigned int cb_idx;
  57 };
  58
  59 size_t ltt_serialize_data(struct rchan_buf *buf, size_t buf_offset,
  60                         struct ltt_serialize_closure *closure,
  61                         void *serialize_private,
  62                         int *largest_align, const char *fmt, va_list *args);
  63
  64 struct ltt_available_probe {
  65         const char *name;               /* probe name */
  66         const char *format;
  67         marker_probe_func *probe_func;
  68         ltt_serialize_cb callbacks[LTT_NR_CALLBACKS];
  69         struct list_head node;          /* registered probes list */
  70 };
  71
  72 struct ltt_probe_private_data {
  73         struct ltt_trace_struct *trace; /*
  74                                          * Target trace, for metadata
  75                                          * or statedump.
  76                                          */
  77         ltt_serialize_cb serializer;    /*
  78                                          * Serialization function override.
  79                                          */
  80         void *serialize_private;        /*
  81                                          * Private data for serialization
  82                                          * functions.
  83                                          */
  84 };
  85
  86 enum ltt_channels {
  87         LTT_CHANNEL_METADATA,
  88         LTT_CHANNEL_UST,
  89 };
  90
  91 struct ltt_active_marker {
  92         struct list_head node;          /* active markers list */
  93         const char *channel;
  94         const char *name;
  95         const char *format;
  96         struct ltt_available_probe *probe;
  97 };
  98
  99 struct marker; //ust//
 100 extern void ltt_vtrace(const struct marker *mdata, void *probe_data,
 101         void *call_data, const char *fmt, va_list *args);
 102 extern void ltt_trace(const struct marker *mdata, void *probe_data,
 103         void *call_data, const char *fmt, ...);
 104
 105 /*
 106  * Unique ID assigned to each registered probe.
 107  */
 108 enum marker_id {
 109         MARKER_ID_SET_MARKER_ID = 0,    /* Static IDs available (range 0-7) */
 110         MARKER_ID_SET_MARKER_FORMAT,
 111         MARKER_ID_COMPACT,              /* Compact IDs (range: 8-127)       */
 112         MARKER_ID_DYNAMIC,              /* Dynamic IDs (range: 128-65535)   */
 113 };
 114
 115 /* static ids 0-1 reserved for internal use. */
 116 #define MARKER_CORE_IDS         2
 117 static inline enum marker_id marker_id_type(uint16_t id)
 118 {
 119         if (id < MARKER_CORE_IDS)
 120                 return (enum marker_id)id;
 121         else
 122                 return MARKER_ID_DYNAMIC;
 123 }
 124
 125 struct user_dbg_data {
 126         unsigned long avail_size;
 127         unsigned long write;
 128         unsigned long read;
 129 };
 130
 131 struct ltt_trace_ops {
 132         /* First 32 bytes cache-hot cacheline */
 133         int (*reserve_slot) (struct ltt_trace_struct *trace,
 134                                 struct ltt_channel_struct *channel,
 135                                 void **transport_data, size_t data_size,
 136                                 size_t *slot_size, long *buf_offset, u64 *tsc,
 137                                 unsigned int *rflags,
 138                                 int largest_align);
 139 //ust// void (*commit_slot) (struct ltt_channel_struct *channel,
 140 //ust//                         void **transport_data, long buf_offset,
 141 //ust//                         size_t slot_size);
 142         void (*wakeup_channel) (struct ltt_channel_struct *ltt_channel);
 143         int (*user_blocking) (struct ltt_trace_struct *trace,
 144                                 unsigned int index, size_t data_size,
 145                                 struct user_dbg_data *dbg);
 146         /* End of first 32 bytes cacheline */
 147         int (*create_dirs) (struct ltt_trace_struct *new_trace);
 148         void (*remove_dirs) (struct ltt_trace_struct *new_trace);
 149         int (*create_channel) (const char *trace_name,
 150                                 struct ltt_trace_struct *trace,
 151                                 struct dentry *dir, const char *channel_name,
 152                                 struct ltt_channel_struct *ltt_chan,
 153                                 unsigned int subbuf_size,
 154                                 unsigned int n_subbufs, int overwrite);
 155         void (*finish_channel) (struct ltt_channel_struct *channel);
 156         void (*remove_channel) (struct ltt_channel_struct *channel);
 157         void (*user_errors) (struct ltt_trace_struct *trace,
 158                                 unsigned int index, size_t data_size,
 159                                 struct user_dbg_data *dbg);
 160 } ____cacheline_aligned;
 161
 162 struct ltt_transport {
 163         char *name;
 164         struct module *owner;
 165         struct list_head node;
 166         struct ltt_trace_ops ops;
 167 };
 168
 169 enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };
 170
 171 #define CHANNEL_FLAG_ENABLE     (1U<<0)
 172 #define CHANNEL_FLAG_OVERWRITE  (1U<<1)
 173
 174 /* Per-trace information - each trace/flight recorder represented by one */
 175 struct ltt_trace_struct {
 176         /* First 32 bytes cache-hot cacheline */
 177         struct list_head list;
 178         struct ltt_trace_ops *ops;
 179         int active;
 180         /* Second 32 bytes cache-hot cacheline */
 181         struct ltt_channel_struct *channels;
 182         unsigned int nr_channels;
 183         u32 freq_scale;
 184         u64 start_freq;
 185         u64 start_tsc;
 186         unsigned long long start_monotonic;
 187         struct timeval          start_time;
 188         struct ltt_channel_setting *settings;
 189         struct {
 190                 struct dentry                   *trace_root;
 191         } dentry;
 192         struct kref kref; /* Each channel has a kref of the trace struct */
 193         struct ltt_transport *transport;
 194         struct kref ltt_transport_kref;
 195         char trace_name[NAME_MAX];
 196 } ____cacheline_aligned;
 197
 198 /* Hardcoded event headers
 199  *
 200  * event header for a trace with active heartbeat : 27 bits timestamps
 201  *
 202  * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
 203  * trace alignment value must be done.
 204  *
 205  * Remember that the C compiler does align each member on the boundary
 206  * equivalent to their own size.
 207  *
 208  * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
 209  * bytes aligned, so the buffer header and trace header are aligned.
 210  *
 211  * Event headers are aligned depending on the trace alignment option.
 212  *
 213  * Note using C structure bitfields for cross-endianness and portability
 214  * concerns.
 215  */
 216
 217 #define LTT_RESERVED_EVENTS     3
 218 #define LTT_EVENT_BITS          5
 219 #define LTT_FREE_EVENTS         ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
 220 #define LTT_TSC_BITS            27
 221 #define LTT_TSC_MASK            ((1 << LTT_TSC_BITS) - 1)
 222
 223 struct ltt_event_header {
 224         u32 id_time;            /* 5 bits event id (MSB); 27 bits time (LSB) */
 225 };
 226
 227 /* Reservation flags */
 228 #define LTT_RFLAG_ID                    (1 << 0)
 229 #define LTT_RFLAG_ID_SIZE               (1 << 1)
 230 #define LTT_RFLAG_ID_SIZE_TSC           (1 << 2)
 231
 232 /*
 233  * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
 234  * specifically with CPU frequency scaling someday, so using an interpolation
 235  * between the start and end of buffer values is not flexible enough. Using an
 236  * immediate frequency value permits to calculate directly the times for parts
 237  * of a buffer that would be before a frequency change.
 238  *
 239  * Keep the natural field alignment for _each field_ within this structure if
 240  * you ever add/remove a field from this header. Packed attribute is not used
 241  * because gcc generates poor code on at least powerpc and mips. Don't ever
 242  * let gcc add padding between the structure elements.
 243  */
 244 struct ltt_subbuffer_header {
 245         uint64_t cycle_count_begin;     /* Cycle count at subbuffer start */
 246         uint64_t cycle_count_end;       /* Cycle count at subbuffer end */
 247         uint32_t magic_number;          /*
 248                                          * Trace magic number.
 249                                          * contains endianness information.
 250                                          */
 251         uint8_t major_version;
 252         uint8_t minor_version;
 253         uint8_t arch_size;              /* Architecture pointer size */
 254         uint8_t alignment;              /* LTT data alignment */
 255         uint64_t start_time_sec;        /* NTP-corrected start time */
 256         uint64_t start_time_usec;
 257         uint64_t start_freq;            /*
 258                                          * Frequency at trace start,
 259                                          * used all along the trace.
 260                                          */
 261         uint32_t freq_scale;            /* Frequency scaling (divisor) */
 262         uint32_t lost_size;             /* Size unused at end of subbuffer */
 263         uint32_t buf_size;              /* Size of this subbuffer */
 264         uint32_t events_lost;           /*
 265                                          * Events lost in this subbuffer since
 266                                          * the beginning of the trace.
 267                                          * (may overflow)
 268                                          */
 269         uint32_t subbuf_corrupt;        /*
 270                                          * Corrupted (lost) subbuffers since
 271                                          * the begginig of the trace.
 272                                          * (may overflow)
 273                                          */
 274         uint8_t header_end[0];          /* End of header */
 275 };
 276
 277 /**
 278  * ltt_subbuffer_header_size - called on buffer-switch to a new sub-buffer
 279  *
 280  * Return header size without padding after the structure. Don't use packed
 281  * structure because gcc generates inefficient code on some architectures
 282  * (powerpc, mips..)
 283  */
 284 static inline size_t ltt_subbuffer_header_size(void)
 285 {
 286         return offsetof(struct ltt_subbuffer_header, header_end);
 287 }
 288
 289 /*
 290  * ltt_get_header_size
 291  *
 292  * Calculate alignment offset to 32-bits. This is the alignment offset of the
 293  * event header.
 294  *
 295  * Important note :
 296  * The event header must be 32-bits. The total offset calculated here :
 297  *
 298  * Alignment of header struct on 32 bits (min arch size, header size)
 299  * + sizeof(header struct)  (32-bits)
 300  * + (opt) u16 (ext. event id)
 301  * + (opt) u16 (event_size) (if event_size == 0xFFFFUL, has ext. event size)
 302  * + (opt) u32 (ext. event size)
 303  * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
 304  *
 305  * The payload must itself determine its own alignment from the biggest type it
 306  * contains.
 307  * */
 308 static inline unsigned char ltt_get_header_size(
 309                 struct ltt_channel_struct *channel,
 310                 size_t offset,
 311                 size_t data_size,
 312                 size_t *before_hdr_pad,
 313                 unsigned int rflags)
 314 {
 315         size_t orig_offset = offset;
 316         size_t padding;
 317
 318         padding = ltt_align(offset, sizeof(struct ltt_event_header));
 319         offset += padding;
 320         offset += sizeof(struct ltt_event_header);
 321
 322         switch (rflags) {
 323         case LTT_RFLAG_ID_SIZE_TSC:
 324                 offset += sizeof(u16) + sizeof(u16);
 325                 if (data_size >= 0xFFFFU)
 326                         offset += sizeof(u32);
 327                 offset += ltt_align(offset, sizeof(u64));
 328                 offset += sizeof(u64);
 329                 break;
 330         case LTT_RFLAG_ID_SIZE:
 331                 offset += sizeof(u16) + sizeof(u16);
 332                 if (data_size >= 0xFFFFU)
 333                         offset += sizeof(u32);
 334                 break;
 335         case LTT_RFLAG_ID:
 336                 offset += sizeof(u16);
 337                 break;
 338         }
 339
 340         *before_hdr_pad = padding;
 341         return offset - orig_offset;
 342 }
 343
 344 /*
 345  * ltt_write_event_header
 346  *
 347  * Writes the event header to the offset (already aligned on 32-bits).
 348  *
 349  * @trace : trace to write to.
 350  * @channel : pointer to the channel structure..
 351  * @buf : buffer to write to.
 352  * @buf_offset : buffer offset to write to (aligned on 32 bits).
 353  * @eID : event ID
 354  * @event_size : size of the event, excluding the event header.
 355  * @tsc : time stamp counter.
 356  * @rflags : reservation flags.
 357  *
 358  * returns : offset where the event data must be written.
 359  */
 360 static inline size_t ltt_write_event_header(struct ltt_trace_struct *trace,
 361                 struct ltt_channel_struct *channel,
 362                 struct rchan_buf *buf, long buf_offset,
 363                 u16 eID, size_t event_size,
 364                 u64 tsc, unsigned int rflags)
 365 {
 366         struct ltt_event_header header;
 367         size_t small_size;
 368
 369         switch (rflags) {
 370         case LTT_RFLAG_ID_SIZE_TSC:
 371                 header.id_time = 29 << LTT_TSC_BITS;
 372                 break;
 373         case LTT_RFLAG_ID_SIZE:
 374                 header.id_time = 30 << LTT_TSC_BITS;
 375                 break;
 376         case LTT_RFLAG_ID:
 377                 header.id_time = 31 << LTT_TSC_BITS;
 378                 break;
 379         default:
 380                 header.id_time = eID << LTT_TSC_BITS;
 381                 break;
 382         }
 383         header.id_time |= (u32)tsc & LTT_TSC_MASK;
 384         ltt_relay_write(buf, buf_offset, &header, sizeof(header));
 385         buf_offset += sizeof(header);
 386
 387         switch (rflags) {
 388         case LTT_RFLAG_ID_SIZE_TSC:
 389                 small_size = min_t(size_t, event_size, 0xFFFFU);
 390                 ltt_relay_write(buf, buf_offset,
 391                         (u16[]){ (u16)eID }, sizeof(u16));
 392                 buf_offset += sizeof(u16);
 393                 ltt_relay_write(buf, buf_offset,
 394                         (u16[]){ (u16)small_size }, sizeof(u16));
 395                 buf_offset += sizeof(u16);
 396                 if (small_size == 0xFFFFU) {
 397                         ltt_relay_write(buf, buf_offset,
 398                                 (u32[]){ (u32)event_size }, sizeof(u32));
 399                         buf_offset += sizeof(u32);
 400                 }
 401                 buf_offset += ltt_align(buf_offset, sizeof(u64));
 402                 ltt_relay_write(buf, buf_offset,
 403                         (u64[]){ (u64)tsc }, sizeof(u64));
 404                 buf_offset += sizeof(u64);
 405                 break;
 406         case LTT_RFLAG_ID_SIZE:
 407                 small_size = min_t(size_t, event_size, 0xFFFFU);
 408                 ltt_relay_write(buf, buf_offset,
 409                         (u16[]){ (u16)eID }, sizeof(u16));
 410                 buf_offset += sizeof(u16);
 411                 ltt_relay_write(buf, buf_offset,
 412                         (u16[]){ (u16)small_size }, sizeof(u16));
 413                 buf_offset += sizeof(u16);
 414                 if (small_size == 0xFFFFU) {
 415                         ltt_relay_write(buf, buf_offset,
 416                                 (u32[]){ (u32)event_size }, sizeof(u32));
 417                         buf_offset += sizeof(u32);
 418                 }
 419                 break;
 420         case LTT_RFLAG_ID:
 421                 ltt_relay_write(buf, buf_offset,
 422                         (u16[]){ (u16)eID }, sizeof(u16));
 423                 buf_offset += sizeof(u16);
 424                 break;
 425         default:
 426                 break;
 427         }
 428
 429         return buf_offset;
 430 }
 431
 432 /* Lockless LTTng */
 433
 434 /*
 435  * ltt_reserve_slot
 436  *
 437  * Atomic slot reservation in a LTTng buffer. It will take care of
 438  * sub-buffer switching.
 439  *
 440  * Parameters:
 441  *
 442  * @trace : the trace structure to log to.
 443  * @channel : the chanel to reserve space into.
 444  * @transport_data : specific transport data.
 445  * @data_size : size of the variable length data to log.
 446  * @slot_size : pointer to total size of the slot (out)
 447  * @buf_offset : pointer to reserve offset (out)
 448  * @tsc : pointer to the tsc at the slot reservation (out)
 449  * @rflags : reservation flags (header specificity)
 450  * @cpu : cpu id
 451  *
 452  * Return : -ENOSPC if not enough space, else 0.
 453  */
 454 static inline int ltt_reserve_slot(
 455                 struct ltt_trace_struct *trace,
 456                 struct ltt_channel_struct *channel,
 457                 void **transport_data,
 458                 size_t data_size,
 459                 size_t *slot_size,
 460                 long *buf_offset,
 461                 u64 *tsc,
 462                 unsigned int *rflags,
 463                 int largest_align)
 464 {
 465         return trace->ops->reserve_slot(trace, channel, transport_data,
 466                         data_size, slot_size, buf_offset, tsc, rflags,
 467                         largest_align);
 468 }
 469
 470
 471 ///*
 472 // * ltt_commit_slot
 473 // *
 474 // * Atomic unordered slot commit. Increments the commit count in the
 475 // * specified sub-buffer, and delivers it if necessary.
 476 // *
 477 // * Parameters:
 478 // *
 479 // * @channel : the chanel to reserve space into.
 480 // * @transport_data : specific transport data.
 481 // * @buf_offset : offset of beginning of reserved slot
 482 // * @slot_size : size of the reserved slot.
 483 // */
 484 //static inline void ltt_commit_slot(
 485 //              struct ltt_channel_struct *channel,
 486 //              void **transport_data,
 487 //              long buf_offset,
 488 //              size_t slot_size)
 489 //{
 490 //      struct ltt_trace_struct *trace = channel->trace;
 491 //
 492 //      trace->ops->commit_slot(channel, transport_data, buf_offset, slot_size);
 493 //}
 494
 495 /*
 496  * Control channels :
 497  * control/metadata
 498  * control/interrupts
 499  * control/...
 500  *
 501  * cpu channel :
 502  * cpu
 503  */
 504
 505 #define LTT_METADATA_CHANNEL            "metadata_state"
 506 #define LTT_UST_CHANNEL                 "ust"
 507
 508 #define LTT_FLIGHT_PREFIX       "flight-"
 509
 510 /* Tracer properties */
 511 //#define LTT_DEFAULT_SUBBUF_SIZE_LOW   65536
 512 #define LTT_DEFAULT_SUBBUF_SIZE_LOW     4096
 513 #define LTT_DEFAULT_N_SUBBUFS_LOW       2
 514 //#define LTT_DEFAULT_SUBBUF_SIZE_MED   262144
 515 #define LTT_DEFAULT_SUBBUF_SIZE_MED     4096
 516 #define LTT_DEFAULT_N_SUBBUFS_MED       2
 517 //#define LTT_DEFAULT_SUBBUF_SIZE_HIGH  1048576
 518 #define LTT_DEFAULT_SUBBUF_SIZE_HIGH    4096
 519 #define LTT_DEFAULT_N_SUBBUFS_HIGH      2
 520 #define LTT_TRACER_MAGIC_NUMBER         0x00D6B7ED
 521 #define LTT_TRACER_VERSION_MAJOR        2
 522 #define LTT_TRACER_VERSION_MINOR        3
 523
 524 /*
 525  * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
 526  * nearly full buffer. User space won't use this last amount of space when in
 527  * blocking mode. This space also includes the event header that would be
 528  * written by this user space event.
 529  */
 530 #define LTT_RESERVE_CRITICAL            4096
 531
 532 /* Register and unregister function pointers */
 533
 534 enum ltt_module_function {
 535         LTT_FUNCTION_RUN_FILTER,
 536         LTT_FUNCTION_FILTER_CONTROL,
 537         LTT_FUNCTION_STATEDUMP
 538 };
 539
 540 void ltt_transport_register(struct ltt_transport *transport);
 541 void ltt_transport_unregister(struct ltt_transport *transport);
 542
 543 /* Exported control function */
 544
 545 union ltt_control_args {
 546         struct {
 547                 enum trace_mode mode;
 548                 unsigned int subbuf_size_low;
 549                 unsigned int n_subbufs_low;
 550                 unsigned int subbuf_size_med;
 551                 unsigned int n_subbufs_med;
 552                 unsigned int subbuf_size_high;
 553                 unsigned int n_subbufs_high;
 554         } new_trace;
 555 };
 556
 557 int _ltt_trace_setup(const char *trace_name);
 558 int ltt_trace_setup(const char *trace_name);
 559 struct ltt_trace_struct *_ltt_trace_find_setup(const char *trace_name);
 560 int ltt_trace_set_type(const char *trace_name, const char *trace_type);
 561 int ltt_trace_set_channel_subbufsize(const char *trace_name,
 562                 const char *channel_name, unsigned int size);
 563 int ltt_trace_set_channel_subbufcount(const char *trace_name,
 564                 const char *channel_name, unsigned int cnt);
 565 int ltt_trace_set_channel_enable(const char *trace_name,
 566                 const char *channel_name, unsigned int enable);
 567 int ltt_trace_set_channel_overwrite(const char *trace_name,
 568                 const char *channel_name, unsigned int overwrite);
 569 int ltt_trace_alloc(const char *trace_name);
 570 int ltt_trace_destroy(const char *trace_name);
 571 int ltt_trace_start(const char *trace_name);
 572 int ltt_trace_stop(const char *trace_name);
 573
 574 enum ltt_filter_control_msg {
 575         LTT_FILTER_DEFAULT_ACCEPT,
 576         LTT_FILTER_DEFAULT_REJECT
 577 };
 578
 579 extern int ltt_filter_control(enum ltt_filter_control_msg msg,
 580                 const char *trace_name);
 581
 582 extern struct dentry *get_filter_root(void);
 583
 584 void ltt_write_trace_header(struct ltt_trace_struct *trace,
 585                 struct ltt_subbuffer_header *header);
 586 extern void ltt_buffer_destroy(struct ltt_channel_struct *ltt_chan);
 587
 588 void ltt_core_register(int (*function)(u8, void *));
 589
 590 void ltt_core_unregister(void);
 591
 592 void ltt_release_trace(struct kref *kref);
 593 void ltt_release_transport(struct kref *kref);
 594
 595 extern int ltt_probe_register(struct ltt_available_probe *pdata);
 596 extern int ltt_probe_unregister(struct ltt_available_probe *pdata);
 597 extern int ltt_marker_connect(const char *channel, const char *mname,
 598                 const char *pname);
 599 extern int ltt_marker_disconnect(const char *channel, const char *mname,
 600                 const char *pname);
 601 extern void ltt_dump_marker_state(struct ltt_trace_struct *trace);
 602
 603 void ltt_lock_traces(void);
 604 void ltt_unlock_traces(void);
 605
 606 struct ltt_trace_struct *_ltt_trace_find(const char *trace_name);
 607
 608 #endif /* _LTT_TRACER_H */