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 library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  22  */
  23
  24 #ifndef _LTT_TRACER_H
  25 #define _LTT_TRACER_H
  26
  27 #include <sys/types.h>
  28 #include <stdarg.h>
  29 //#include "list.h"
  30 #include <ust/kernelcompat.h>
  31 #include "buffer.h"
  32 #include "relay.h"
  33 #include "channels.h"
  34 #include "tracercore.h"
  35 #include <ust/marker.h>
  36
  37 /* Number of bytes to log with a read/write event */
  38 #define LTT_LOG_RW_SIZE                 32L
  39
  40 /* Interval (in jiffies) at which the LTT per-CPU timer fires */
  41 #define LTT_PERCPU_TIMER_INTERVAL       1
  42
  43 #ifndef LTT_ARCH_TYPE
  44 #define LTT_ARCH_TYPE                   LTT_ARCH_TYPE_UNDEFINED
  45 #endif
  46
  47 #ifndef LTT_ARCH_VARIANT
  48 #define LTT_ARCH_VARIANT                LTT_ARCH_VARIANT_NONE
  49 #endif
  50
  51 struct ltt_active_marker;
  52
  53 /* Maximum number of callbacks per marker */
  54 #define LTT_NR_CALLBACKS        10
  55
  56 struct ltt_serialize_closure;
  57 struct ltt_probe_private_data;
  58
  59 /* Serialization callback '%k' */
  60 typedef size_t (*ltt_serialize_cb)(struct rchan_buf *buf, size_t buf_offset,
  61                         struct ltt_serialize_closure *closure,
  62                         void *serialize_private, int *largest_align,
  63                         const char *fmt, va_list *args);
  64
  65 struct ltt_serialize_closure {
  66         ltt_serialize_cb *callbacks;
  67         long cb_args[LTT_NR_CALLBACKS];
  68         unsigned int cb_idx;
  69 };
  70
  71 extern size_t ltt_serialize_data(struct rchan_buf *buf, size_t buf_offset,
  72                         struct ltt_serialize_closure *closure,
  73                         void *serialize_private,
  74                         int *largest_align, const char *fmt, va_list *args);
  75
  76 struct ltt_available_probe {
  77         const char *name;               /* probe name */
  78         const char *format;
  79         marker_probe_func *probe_func;
  80         ltt_serialize_cb callbacks[LTT_NR_CALLBACKS];
  81         struct list_head node;          /* registered probes list */
  82 };
  83
  84 struct ltt_probe_private_data {
  85         struct ltt_trace_struct *trace; /*
  86                                          * Target trace, for metadata
  87                                          * or statedump.
  88                                          */
  89         ltt_serialize_cb serializer;    /*
  90                                          * Serialization function override.
  91                                          */
  92         void *serialize_private;        /*
  93                                          * Private data for serialization
  94                                          * functions.
  95                                          */
  96 };
  97
  98 enum ltt_channels {
  99         LTT_CHANNEL_METADATA,
 100         LTT_CHANNEL_UST,
 101 };
 102
 103 struct ltt_active_marker {
 104         struct list_head node;          /* active markers list */
 105         const char *channel;
 106         const char *name;
 107         const char *format;
 108         struct ltt_available_probe *probe;
 109 };
 110
 111 struct marker; //ust//
 112 extern void ltt_vtrace(const struct marker *mdata, void *probe_data,
 113         struct registers *regs, void *call_data, const char *fmt, va_list *args);
 114 extern void ltt_trace(const struct marker *mdata, void *probe_data,
 115         struct registers *regs, void *call_data, const char *fmt, ...);
 116
 117 /*
 118  * Unique ID assigned to each registered probe.
 119  */
 120 enum marker_id {
 121         MARKER_ID_SET_MARKER_ID = 0,    /* Static IDs available (range 0-7) */
 122         MARKER_ID_SET_MARKER_FORMAT,
 123         MARKER_ID_COMPACT,              /* Compact IDs (range: 8-127)       */
 124         MARKER_ID_DYNAMIC,              /* Dynamic IDs (range: 128-65535)   */
 125 };
 126
 127 /* static ids 0-1 reserved for internal use. */
 128 #define MARKER_CORE_IDS         2
 129 static inline enum marker_id marker_id_type(uint16_t id)
 130 {
 131         if (id < MARKER_CORE_IDS)
 132                 return (enum marker_id)id;
 133         else
 134                 return MARKER_ID_DYNAMIC;
 135 }
 136
 137 struct user_dbg_data {
 138         unsigned long avail_size;
 139         unsigned long write;
 140         unsigned long read;
 141 };
 142
 143 struct ltt_trace_ops {
 144         /* First 32 bytes cache-hot cacheline */
 145         int (*reserve_slot) (struct ltt_trace_struct *trace,
 146                                 struct ltt_channel_struct *channel,
 147                                 void **transport_data, size_t data_size,
 148                                 size_t *slot_size, long *buf_offset, u64 *tsc,
 149                                 unsigned int *rflags,
 150                                 int largest_align);
 151 //ust// void (*commit_slot) (struct ltt_channel_struct *channel,
 152 //ust//                         void **transport_data, long buf_offset,
 153 //ust//                         size_t slot_size);
 154         void (*wakeup_channel) (struct ltt_channel_struct *ltt_channel);
 155         int (*user_blocking) (struct ltt_trace_struct *trace,
 156                                 unsigned int index, size_t data_size,
 157                                 struct user_dbg_data *dbg);
 158         /* End of first 32 bytes cacheline */
 159         int (*create_dirs) (struct ltt_trace_struct *new_trace);
 160         void (*remove_dirs) (struct ltt_trace_struct *new_trace);
 161         int (*create_channel) (const char *trace_name,
 162                                 struct ltt_trace_struct *trace,
 163                                 struct dentry *dir, const char *channel_name,
 164                                 struct ltt_channel_struct *ltt_chan,
 165                                 unsigned int subbuf_size,
 166                                 unsigned int n_subbufs, int overwrite);
 167         void (*finish_channel) (struct ltt_channel_struct *channel);
 168         void (*remove_channel) (struct ltt_channel_struct *channel);
 169         void (*user_errors) (struct ltt_trace_struct *trace,
 170                                 unsigned int index, size_t data_size,
 171                                 struct user_dbg_data *dbg);
 172 } ____cacheline_aligned;
 173
 174 struct ltt_transport {
 175         char *name;
 176         struct module *owner;
 177         struct list_head node;
 178         struct ltt_trace_ops ops;
 179 };
 180
 181 enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };
 182
 183 #define CHANNEL_FLAG_ENABLE     (1U<<0)
 184 #define CHANNEL_FLAG_OVERWRITE  (1U<<1)
 185
 186 /* Per-trace information - each trace/flight recorder represented by one */
 187 struct ltt_trace_struct {
 188         /* First 32 bytes cache-hot cacheline */
 189         struct list_head list;
 190         struct ltt_trace_ops *ops;
 191         int active;
 192         /* Second 32 bytes cache-hot cacheline */
 193         struct ltt_channel_struct *channels;
 194         unsigned int nr_channels;
 195         u32 freq_scale;
 196         u64 start_freq;
 197         u64 start_tsc;
 198         unsigned long long start_monotonic;
 199         struct timeval          start_time;
 200         struct ltt_channel_setting *settings;
 201         struct {
 202                 struct dentry                   *trace_root;
 203         } dentry;
 204         struct kref kref; /* Each channel has a kref of the trace struct */
 205         struct ltt_transport *transport;
 206         struct kref ltt_transport_kref;
 207         char trace_name[NAME_MAX];
 208 } ____cacheline_aligned;
 209
 210 /* Hardcoded event headers
 211  *
 212  * event header for a trace with active heartbeat : 27 bits timestamps
 213  *
 214  * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
 215  * trace alignment value must be done.
 216  *
 217  * Remember that the C compiler does align each member on the boundary
 218  * equivalent to their own size.
 219  *
 220  * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
 221  * bytes aligned, so the buffer header and trace header are aligned.
 222  *
 223  * Event headers are aligned depending on the trace alignment option.
 224  *
 225  * Note using C structure bitfields for cross-endianness and portability
 226  * concerns.
 227  */
 228
 229 #define LTT_RESERVED_EVENTS     3
 230 #define LTT_EVENT_BITS          5
 231 #define LTT_FREE_EVENTS         ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
 232 #define LTT_TSC_BITS            27
 233 #define LTT_TSC_MASK            ((1 << LTT_TSC_BITS) - 1)
 234
 235 struct ltt_event_header {
 236         u32 id_time;            /* 5 bits event id (MSB); 27 bits time (LSB) */
 237 };
 238
 239 /* Reservation flags */
 240 #define LTT_RFLAG_ID                    (1 << 0)
 241 #define LTT_RFLAG_ID_SIZE               (1 << 1)
 242 #define LTT_RFLAG_ID_SIZE_TSC           (1 << 2)
 243
 244 /*
 245  * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
 246  * specifically with CPU frequency scaling someday, so using an interpolation
 247  * between the start and end of buffer values is not flexible enough. Using an
 248  * immediate frequency value permits to calculate directly the times for parts
 249  * of a buffer that would be before a frequency change.
 250  *
 251  * Keep the natural field alignment for _each field_ within this structure if
 252  * you ever add/remove a field from this header. Packed attribute is not used
 253  * because gcc generates poor code on at least powerpc and mips. Don't ever
 254  * let gcc add padding between the structure elements.
 255  */
 256 struct ltt_subbuffer_header {
 257         uint64_t cycle_count_begin;     /* Cycle count at subbuffer start */
 258         uint64_t cycle_count_end;       /* Cycle count at subbuffer end */
 259         uint32_t magic_number;          /*
 260                                          * Trace magic number.
 261                                          * contains endianness information.
 262                                          */
 263         uint8_t major_version;
 264         uint8_t minor_version;
 265         uint8_t arch_size;              /* Architecture pointer size */
 266         uint8_t alignment;              /* LTT data alignment */
 267         uint64_t start_time_sec;        /* NTP-corrected start time */
 268         uint64_t start_time_usec;
 269         uint64_t start_freq;            /*
 270                                          * Frequency at trace start,
 271                                          * used all along the trace.
 272                                          */
 273         uint32_t freq_scale;            /* Frequency scaling (divisor) */
 274         uint32_t lost_size;             /* Size unused at end of subbuffer */
 275         uint32_t buf_size;              /* Size of this subbuffer */
 276         uint32_t events_lost;           /*
 277                                          * Events lost in this subbuffer since
 278                                          * the beginning of the trace.
 279                                          * (may overflow)
 280                                          */
 281         uint32_t subbuf_corrupt;        /*
 282                                          * Corrupted (lost) subbuffers since
 283                                          * the begginig of the trace.
 284                                          * (may overflow)
 285                                          */
 286         uint8_t header_end[0];          /* End of header */
 287 };
 288
 289 /**
 290  * ltt_subbuffer_header_size - called on buffer-switch to a new sub-buffer
 291  *
 292  * Return header size without padding after the structure. Don't use packed
 293  * structure because gcc generates inefficient code on some architectures
 294  * (powerpc, mips..)
 295  */
 296 static inline size_t ltt_subbuffer_header_size(void)
 297 {
 298         return offsetof(struct ltt_subbuffer_header, header_end);
 299 }
 300
 301 /*
 302  * ltt_get_header_size
 303  *
 304  * Calculate alignment offset to 32-bits. This is the alignment offset of the
 305  * event header.
 306  *
 307  * Important note :
 308  * The event header must be 32-bits. The total offset calculated here :
 309  *
 310  * Alignment of header struct on 32 bits (min arch size, header size)
 311  * + sizeof(header struct)  (32-bits)
 312  * + (opt) u16 (ext. event id)
 313  * + (opt) u16 (event_size) (if event_size == 0xFFFFUL, has ext. event size)
 314  * + (opt) u32 (ext. event size)
 315  * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
 316  *
 317  * The payload must itself determine its own alignment from the biggest type it
 318  * contains.
 319  * */
 320 static inline unsigned char ltt_get_header_size(
 321                 struct ltt_channel_struct *channel,
 322                 size_t offset,
 323                 size_t data_size,
 324                 size_t *before_hdr_pad,
 325                 unsigned int rflags)
 326 {
 327         size_t orig_offset = offset;
 328         size_t padding;
 329
 330         padding = ltt_align(offset, sizeof(struct ltt_event_header));
 331         offset += padding;
 332         offset += sizeof(struct ltt_event_header);
 333
 334         switch (rflags) {
 335         case LTT_RFLAG_ID_SIZE_TSC:
 336                 offset += sizeof(u16) + sizeof(u16);
 337                 if (data_size >= 0xFFFFU)
 338                         offset += sizeof(u32);
 339                 offset += ltt_align(offset, sizeof(u64));
 340                 offset += sizeof(u64);
 341                 break;
 342         case LTT_RFLAG_ID_SIZE:
 343                 offset += sizeof(u16) + sizeof(u16);
 344                 if (data_size >= 0xFFFFU)
 345                         offset += sizeof(u32);
 346                 break;
 347         case LTT_RFLAG_ID:
 348                 offset += sizeof(u16);
 349                 break;
 350         }
 351
 352         *before_hdr_pad = padding;
 353         return offset - orig_offset;
 354 }
 355
 356 /*
 357  * ltt_write_event_header
 358  *
 359  * Writes the event header to the offset (already aligned on 32-bits).
 360  *
 361  * @trace : trace to write to.
 362  * @channel : pointer to the channel structure..
 363  * @buf : buffer to write to.
 364  * @buf_offset : buffer offset to write to (aligned on 32 bits).
 365  * @eID : event ID
 366  * @event_size : size of the event, excluding the event header.
 367  * @tsc : time stamp counter.
 368  * @rflags : reservation flags.
 369  *
 370  * returns : offset where the event data must be written.
 371  */
 372 static inline size_t ltt_write_event_header(struct ltt_trace_struct *trace,
 373                 struct ltt_channel_struct *channel,
 374                 struct rchan_buf *buf, long buf_offset,
 375                 u16 eID, size_t event_size,
 376                 u64 tsc, unsigned int rflags)
 377 {
 378         struct ltt_event_header header;
 379         size_t small_size;
 380
 381         switch (rflags) {
 382         case LTT_RFLAG_ID_SIZE_TSC:
 383                 header.id_time = 29 << LTT_TSC_BITS;
 384                 break;
 385         case LTT_RFLAG_ID_SIZE:
 386                 header.id_time = 30 << LTT_TSC_BITS;
 387                 break;
 388         case LTT_RFLAG_ID:
 389                 header.id_time = 31 << LTT_TSC_BITS;
 390                 break;
 391         default:
 392                 header.id_time = eID << LTT_TSC_BITS;
 393                 break;
 394         }
 395         header.id_time |= (u32)tsc & LTT_TSC_MASK;
 396         ltt_relay_write(buf, buf_offset, &header, sizeof(header));
 397         buf_offset += sizeof(header);
 398
 399         switch (rflags) {
 400         case LTT_RFLAG_ID_SIZE_TSC:
 401                 small_size = min_t(size_t, event_size, 0xFFFFU);
 402                 ltt_relay_write(buf, buf_offset,
 403                         (u16[]){ (u16)eID }, sizeof(u16));
 404                 buf_offset += sizeof(u16);
 405                 ltt_relay_write(buf, buf_offset,
 406                         (u16[]){ (u16)small_size }, sizeof(u16));
 407                 buf_offset += sizeof(u16);
 408                 if (small_size == 0xFFFFU) {
 409                         ltt_relay_write(buf, buf_offset,
 410                                 (u32[]){ (u32)event_size }, sizeof(u32));
 411                         buf_offset += sizeof(u32);
 412                 }
 413                 buf_offset += ltt_align(buf_offset, sizeof(u64));
 414                 ltt_relay_write(buf, buf_offset,
 415                         (u64[]){ (u64)tsc }, sizeof(u64));
 416                 buf_offset += sizeof(u64);
 417                 break;
 418         case LTT_RFLAG_ID_SIZE:
 419                 small_size = min_t(size_t, event_size, 0xFFFFU);
 420                 ltt_relay_write(buf, buf_offset,
 421                         (u16[]){ (u16)eID }, sizeof(u16));
 422                 buf_offset += sizeof(u16);
 423                 ltt_relay_write(buf, buf_offset,
 424                         (u16[]){ (u16)small_size }, sizeof(u16));
 425                 buf_offset += sizeof(u16);
 426                 if (small_size == 0xFFFFU) {
 427                         ltt_relay_write(buf, buf_offset,
 428                                 (u32[]){ (u32)event_size }, sizeof(u32));
 429                         buf_offset += sizeof(u32);
 430                 }
 431                 break;
 432         case LTT_RFLAG_ID:
 433                 ltt_relay_write(buf, buf_offset,
 434                         (u16[]){ (u16)eID }, sizeof(u16));
 435                 buf_offset += sizeof(u16);
 436                 break;
 437         default:
 438                 break;
 439         }
 440
 441         return buf_offset;
 442 }
 443
 444 /* Lockless LTTng */
 445
 446 /*
 447  * ltt_reserve_slot
 448  *
 449  * Atomic slot reservation in a LTTng buffer. It will take care of
 450  * sub-buffer switching.
 451  *
 452  * Parameters:
 453  *
 454  * @trace : the trace structure to log to.
 455  * @channel : the chanel to reserve space into.
 456  * @transport_data : specific transport data.
 457  * @data_size : size of the variable length data to log.
 458  * @slot_size : pointer to total size of the slot (out)
 459  * @buf_offset : pointer to reserve offset (out)
 460  * @tsc : pointer to the tsc at the slot reservation (out)
 461  * @rflags : reservation flags (header specificity)
 462  * @cpu : cpu id
 463  *
 464  * Return : -ENOSPC if not enough space, else 0.
 465  */
 466 static inline int ltt_reserve_slot(
 467                 struct ltt_trace_struct *trace,
 468                 struct ltt_channel_struct *channel,
 469                 void **transport_data,
 470                 size_t data_size,
 471                 size_t *slot_size,
 472                 long *buf_offset,
 473                 u64 *tsc,
 474                 unsigned int *rflags,
 475                 int largest_align)
 476 {
 477         return trace->ops->reserve_slot(trace, channel, transport_data,
 478                         data_size, slot_size, buf_offset, tsc, rflags,
 479                         largest_align);
 480 }
 481
 482
 483 ///*
 484 // * ltt_commit_slot
 485 // *
 486 // * Atomic unordered slot commit. Increments the commit count in the
 487 // * specified sub-buffer, and delivers it if necessary.
 488 // *
 489 // * Parameters:
 490 // *
 491 // * @channel : the chanel to reserve space into.
 492 // * @transport_data : specific transport data.
 493 // * @buf_offset : offset of beginning of reserved slot
 494 // * @slot_size : size of the reserved slot.
 495 // */
 496 //static inline void ltt_commit_slot(
 497 //              struct ltt_channel_struct *channel,
 498 //              void **transport_data,
 499 //              long buf_offset,
 500 //              size_t slot_size)
 501 //{
 502 //      struct ltt_trace_struct *trace = channel->trace;
 503 //
 504 //      trace->ops->commit_slot(channel, transport_data, buf_offset, slot_size);
 505 //}
 506
 507 /*
 508  * Control channels :
 509  * control/metadata
 510  * control/interrupts
 511  * control/...
 512  *
 513  * cpu channel :
 514  * cpu
 515  */
 516
 517 #define LTT_METADATA_CHANNEL            "metadata_state"
 518 #define LTT_UST_CHANNEL                 "ust"
 519
 520 #define LTT_FLIGHT_PREFIX       "flight-"
 521
 522 /* Tracer properties */
 523 //#define LTT_DEFAULT_SUBBUF_SIZE_LOW   134217728
 524 #define LTT_DEFAULT_SUBBUF_SIZE_LOW     65536
 525 //#define LTT_DEFAULT_SUBBUF_SIZE_LOW   4096
 526 #define LTT_DEFAULT_N_SUBBUFS_LOW       2
 527 //#define LTT_DEFAULT_SUBBUF_SIZE_MED   134217728
 528 #define LTT_DEFAULT_SUBBUF_SIZE_MED     262144
 529 //#define LTT_DEFAULT_SUBBUF_SIZE_MED   4096
 530 #define LTT_DEFAULT_N_SUBBUFS_MED       2
 531 //#define LTT_DEFAULT_SUBBUF_SIZE_HIGH  134217728
 532 #define LTT_DEFAULT_SUBBUF_SIZE_HIGH    1048576
 533 //#define LTT_DEFAULT_SUBBUF_SIZE_HIGH  4096
 534 #define LTT_DEFAULT_N_SUBBUFS_HIGH      2
 535 #define LTT_TRACER_MAGIC_NUMBER         0x00D6B7ED
 536 #define LTT_TRACER_VERSION_MAJOR        2
 537 #define LTT_TRACER_VERSION_MINOR        3
 538
 539 /*
 540  * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
 541  * nearly full buffer. User space won't use this last amount of space when in
 542  * blocking mode. This space also includes the event header that would be
 543  * written by this user space event.
 544  */
 545 #define LTT_RESERVE_CRITICAL            4096
 546
 547 /* Register and unregister function pointers */
 548
 549 enum ltt_module_function {
 550         LTT_FUNCTION_RUN_FILTER,
 551         LTT_FUNCTION_FILTER_CONTROL,
 552         LTT_FUNCTION_STATEDUMP
 553 };
 554
 555 extern void ltt_transport_register(struct ltt_transport *transport);
 556 extern void ltt_transport_unregister(struct ltt_transport *transport);
 557
 558 /* Exported control function */
 559
 560 union ltt_control_args {
 561         struct {
 562                 enum trace_mode mode;
 563                 unsigned int subbuf_size_low;
 564                 unsigned int n_subbufs_low;
 565                 unsigned int subbuf_size_med;
 566                 unsigned int n_subbufs_med;
 567                 unsigned int subbuf_size_high;
 568                 unsigned int n_subbufs_high;
 569         } new_trace;
 570 };
 571
 572 extern int _ltt_trace_setup(const char *trace_name);
 573 extern int ltt_trace_setup(const char *trace_name);
 574 extern struct ltt_trace_struct *_ltt_trace_find_setup(const char *trace_name);
 575 extern int ltt_trace_set_type(const char *trace_name, const char *trace_type);
 576 extern int ltt_trace_set_channel_subbufsize(const char *trace_name,
 577                 const char *channel_name, unsigned int size);
 578 extern int ltt_trace_set_channel_subbufcount(const char *trace_name,
 579                 const char *channel_name, unsigned int cnt);
 580 extern int ltt_trace_set_channel_enable(const char *trace_name,
 581                 const char *channel_name, unsigned int enable);
 582 extern int ltt_trace_set_channel_overwrite(const char *trace_name,
 583                 const char *channel_name, unsigned int overwrite);
 584 extern int ltt_trace_alloc(const char *trace_name);
 585 extern int ltt_trace_destroy(const char *trace_name);
 586 extern int ltt_trace_start(const char *trace_name);
 587 extern int ltt_trace_stop(const char *trace_name);
 588
 589 enum ltt_filter_control_msg {
 590         LTT_FILTER_DEFAULT_ACCEPT,
 591         LTT_FILTER_DEFAULT_REJECT
 592 };
 593
 594 extern int ltt_filter_control(enum ltt_filter_control_msg msg,
 595                 const char *trace_name);
 596
 597 extern struct dentry *get_filter_root(void);
 598
 599 extern void ltt_write_trace_header(struct ltt_trace_struct *trace,
 600                 struct ltt_subbuffer_header *header);
 601 extern void ltt_buffer_destroy(struct ltt_channel_struct *ltt_chan);
 602
 603 extern void ltt_core_register(int (*function)(u8, void *));
 604
 605 extern void ltt_core_unregister(void);
 606
 607 extern void ltt_release_trace(struct kref *kref);
 608 extern void ltt_release_transport(struct kref *kref);
 609
 610 extern int ltt_probe_register(struct ltt_available_probe *pdata);
 611 extern int ltt_probe_unregister(struct ltt_available_probe *pdata);
 612 extern int ltt_marker_connect(const char *channel, const char *mname,
 613                 const char *pname);
 614 extern int ltt_marker_disconnect(const char *channel, const char *mname,
 615                 const char *pname);
 616 extern void ltt_dump_marker_state(struct ltt_trace_struct *trace);
 617
 618 extern void ltt_lock_traces(void);
 619 extern void ltt_unlock_traces(void);
 620
 621 extern struct ltt_trace_struct *_ltt_trace_find(const char *trace_name);
 622
 623 #endif /* _LTT_TRACER_H */