ltt-tracer.h

   1 /*
   2  * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
   3  *
   4  * This contains the definitions for the Linux Trace Toolkit tracer.
   5  *
   6  * Dual LGPL v2.1/GPL v2 license.
   7  */
   8
   9 #ifndef _LTT_TRACER_H
  10 #define _LTT_TRACER_H
  11
  12 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
  13 /* Align data on its natural alignment */
  14 #define RING_BUFFER_ALIGN
  15 #endif
  16
  17 #include <linux/ringbuffer/config.h>
  18
  19 #include <stdarg.h>
  20 #include <linux/types.h>
  21 #include <linux/limits.h>
  22 #include <linux/list.h>
  23 #include <linux/cache.h>
  24 #include <linux/kernel.h>
  25 #include <linux/timex.h>
  26 #include <linux/wait.h>
  27 #include <linux/marker.h>
  28 #include <linux/trace-clock.h>
  29 #include <asm/atomic.h>
  30 #include <asm/local.h>
  31
  32 #include "ltt-tracer-core.h"
  33 #include "ltt-channels.h"
  34
  35 /* Number of bytes to log with a read/write event */
  36 #define LTT_LOG_RW_SIZE                 32L
  37
  38 struct ltt_active_marker;
  39
  40 /* Maximum number of callbacks per marker */
  41 #define LTT_NR_CALLBACKS        10
  42
  43 struct ltt_serialize_closure {
  44         ltt_serialize_cb *callbacks;
  45         long cb_args[LTT_NR_CALLBACKS];
  46         unsigned int cb_idx;
  47 };
  48
  49 size_t ltt_serialize_data(struct ltt_chanbuf *buf, size_t buf_offset,
  50                           struct ltt_serialize_closure *closure,
  51                           void *serialize_private, unsigned int stack_pos_ctx,
  52                           int *largest_align, const char *fmt, va_list *args);
  53
  54 struct ltt_available_probe {
  55         const char *name;               /* probe name */
  56         const char *format;
  57         marker_probe_func *probe_func;
  58         ltt_serialize_cb callbacks[LTT_NR_CALLBACKS];
  59         struct list_head node;          /* registered probes list */
  60 };
  61
  62 enum ltt_channels {
  63         LTT_CHANNEL_METADATA,
  64         LTT_CHANNEL_FD_STATE,
  65         LTT_CHANNEL_GLOBAL_STATE,
  66         LTT_CHANNEL_IRQ_STATE,
  67         LTT_CHANNEL_MODULE_STATE,
  68         LTT_CHANNEL_NETIF_STATE,
  69         LTT_CHANNEL_SOFTIRQ_STATE,
  70         LTT_CHANNEL_SWAP_STATE,
  71         LTT_CHANNEL_SYSCALL_STATE,
  72         LTT_CHANNEL_TASK_STATE,
  73         LTT_CHANNEL_VM_STATE,
  74         LTT_CHANNEL_FS,
  75         LTT_CHANNEL_INPUT,
  76         LTT_CHANNEL_IPC,
  77         LTT_CHANNEL_KERNEL,
  78         LTT_CHANNEL_MM,
  79         LTT_CHANNEL_RCU,
  80         LTT_CHANNEL_DEFAULT,
  81 };
  82
  83 struct ltt_active_marker {
  84         struct list_head node;          /* active markers list */
  85         const char *channel;
  86         const char *name;
  87         const char *format;
  88         struct ltt_available_probe *probe;
  89 };
  90
  91 extern void ltt_vtrace(const struct marker *mdata, void *probe_data,
  92                        void *call_data, const char *fmt, va_list *args);
  93 extern void ltt_trace(const struct marker *mdata, void *probe_data,
  94                       void *call_data, const char *fmt, ...);
  95
  96 size_t ltt_serialize_printf(struct ltt_chanbuf *buf, unsigned long buf_offset,
  97                             size_t *msg_size, char *output, size_t outlen,
  98                             const char *fmt);
  99
 100 /*
 101  * Unique ID assigned to each registered probe.
 102  */
 103 enum marker_id {
 104         MARKER_ID_SET_MARKER_ID = 0,    /* Static IDs available (range 0-7) */
 105         MARKER_ID_SET_MARKER_FORMAT,
 106         MARKER_ID_COMPACT,              /* Compact IDs (range: 8-127)       */
 107         MARKER_ID_DYNAMIC,              /* Dynamic IDs (range: 128-65535)   */
 108 };
 109
 110 /* static ids 0-1 reserved for internal use. */
 111 #define MARKER_CORE_IDS         2
 112 static __inline__ enum marker_id marker_id_type(uint16_t id)
 113 {
 114         if (id < MARKER_CORE_IDS)
 115                 return (enum marker_id)id;
 116         else
 117                 return MARKER_ID_DYNAMIC;
 118 }
 119
 120 struct user_dbg_data {
 121         unsigned long avail_size;
 122         unsigned long write;
 123         unsigned long read;
 124 };
 125
 126 struct ltt_trace_ops {
 127         int (*create_dirs) (struct ltt_trace *new_trace);
 128         void (*remove_dirs) (struct ltt_trace *new_trace);
 129         struct channel *ltt_channel_create(const char *name,
 130                                 struct ltt_trace *trace,
 131                                 void *buf_addr,
 132                                 size_t subbuf_size, size_t num_subbuf,
 133                                 unsigned int switch_timer_interval,
 134                                 unsigned int read_timer_interval);
 135         void ltt_channel_destroy(struct channel *chan);
 136 };
 137
 138 struct ltt_transport {
 139         char *name;
 140         struct module *owner;
 141         struct list_head node;
 142         struct ltt_trace_ops ops;
 143 };
 144
 145 enum trace_mode { LTT_TRACE_NORMAL, LTT_TRACE_FLIGHT, LTT_TRACE_HYBRID };
 146
 147 #define CHANNEL_FLAG_ENABLE     (1U<<0)
 148 #define CHANNEL_FLAG_OVERWRITE  (1U<<1)
 149
 150 /* Per-trace information - each trace/flight recorder represented by one */
 151 struct ltt_trace {
 152         /* First 32 bytes cache-hot cacheline */
 153         struct list_head list;
 154         struct ltt_chan **channels;
 155         unsigned int nr_channels;
 156         int active;
 157         /* Second 32 bytes cache-hot cacheline */
 158         struct ltt_trace_ops *ops;
 159         u32 freq_scale;
 160         u64 start_freq;
 161         u64 start_tsc;
 162         unsigned long long start_monotonic;
 163         struct timeval          start_time;
 164         struct ltt_channel_setting *settings;
 165         struct {
 166                 struct dentry                   *trace_root;
 167                 struct dentry                   *ascii_root;
 168         } dentry;
 169         struct kref kref; /* Each channel has a kref of the trace struct */
 170         struct ltt_transport *transport;
 171         struct kref ltt_transport_kref;
 172         wait_queue_head_t kref_wq; /* Place for ltt_trace_destroy to sleep */
 173         char trace_name[NAME_MAX];
 174 } ____cacheline_aligned;
 175
 176 /*
 177  * Hardcoded event headers
 178  *
 179  * event header for a trace with active heartbeat : 27 bits timestamps
 180  *
 181  * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
 182  * trace alignment value must be done.
 183  *
 184  * Remember that the C compiler does align each member on the boundary
 185  * equivalent to their own size.
 186  *
 187  * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
 188  * bytes aligned, so the buffer header and trace header are aligned.
 189  *
 190  * Event headers are aligned depending on the trace alignment option.
 191  *
 192  * Note using C structure bitfields for cross-endianness and portability
 193  * concerns.
 194  */
 195
 196 #define LTT_RESERVED_EVENTS     3
 197 #define LTT_EVENT_BITS          5
 198 #define LTT_FREE_EVENTS         ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
 199 #define LTT_TSC_BITS            27
 200 #define LTT_TSC_MASK            ((1 << LTT_TSC_BITS) - 1)
 201
 202 struct event_header {
 203         u32 id_time;            /* 5 bits event id (MSB); 27 bits time (LSB) */
 204 };
 205
 206 /* Reservation flags */
 207 #define LTT_RFLAG_ID                    (1 << 0)
 208 #define LTT_RFLAG_ID_SIZE               (1 << 1)
 209 #define LTT_RFLAG_ID_SIZE_TSC           (1 << 2)
 210
 211 #define LTT_MAX_SMALL_SIZE              0xFFFFU
 212
 213 /*
 214  * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
 215  * specifically with CPU frequency scaling someday, so using an interpolation
 216  * between the start and end of buffer values is not flexible enough. Using an
 217  * immediate frequency value permits to calculate directly the times for parts
 218  * of a buffer that would be before a frequency change.
 219  *
 220  * Keep the natural field alignment for _each field_ within this structure if
 221  * you ever add/remove a field from this header. Packed attribute is not used
 222  * because gcc generates poor code on at least powerpc and mips. Don't ever
 223  * let gcc add padding between the structure elements.
 224  */
 225 struct subbuffer_header {
 226         uint64_t cycle_count_begin;     /* Cycle count at subbuffer start */
 227         uint64_t cycle_count_end;       /* Cycle count at subbuffer end */
 228         uint32_t magic_number;          /*
 229                                          * Trace magic number.
 230                                          * contains endianness information.
 231                                          */
 232         uint8_t major_version;
 233         uint8_t minor_version;
 234         uint8_t arch_size;              /* Architecture pointer size */
 235         uint8_t alignment;              /* LTT data alignment */
 236         uint64_t start_time_sec;        /* NTP-corrected start time */
 237         uint64_t start_time_usec;
 238         uint64_t start_freq;            /*
 239                                          * Frequency at trace start,
 240                                          * used all along the trace.
 241                                          */
 242         uint32_t freq_scale;            /* Frequency scaling (divisor) */
 243         uint32_t data_size;             /* Size of data in subbuffer */
 244         uint32_t sb_size;               /* Subbuffer size (include padding) */
 245         uint32_t events_lost;           /*
 246                                          * Events lost in this subbuffer since
 247                                          * the beginning of the trace.
 248                                          * (may overflow)
 249                                          */
 250         uint32_t subbuf_corrupt;        /*
 251                                          * Corrupted (lost) subbuffers since
 252                                          * the begginig of the trace.
 253                                          * (may overflow)
 254                                          */
 255         uint8_t header_end[0];          /* End of header */
 256 };
 257
 258 static inline notrace u64 lib_ring_buffer_clock_read(struct channel *chan)
 259 {
 260         return trace_clock_read64();
 261 }
 262
 263 /*
 264  * record_header_size - Calculate the header size and padding necessary.
 265  * @config: ring buffer instance configuration
 266  * @chan: channel
 267  * @offset: offset in the write buffer
 268  * @data_size: size of the payload
 269  * @pre_header_padding: padding to add before the header (output)
 270  * @rflags: reservation flags
 271  * @ctx: reservation context
 272  *
 273  * Returns the event header size (including padding).
 274  *
 275  * Important note :
 276  * The event header must be 32-bits. The total offset calculated here :
 277  *
 278  * Alignment of header struct on 32 bits (min arch size, header size)
 279  * + sizeof(header struct)  (32-bits)
 280  * + (opt) u16 (ext. event id)
 281  * + (opt) u16 (event_size)
 282  *             (if event_size == LTT_MAX_SMALL_SIZE, has ext. event size)
 283  * + (opt) u32 (ext. event size)
 284  * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
 285  *
 286  * The payload must itself determine its own alignment from the biggest type it
 287  * contains.
 288  */
 289 static __inline__
 290 unsigned char record_header_size(const struct lib_ring_buffer_config *config,
 291                                  struct channel *chan, size_t offset,
 292                                  size_t data_size, size_t *pre_header_padding,
 293                                  unsigned int rflags,
 294                                  struct lib_ring_buffer_ctx *ctx)
 295 {
 296         size_t orig_offset = offset;
 297         size_t padding;
 298
 299         BUILD_BUG_ON(sizeof(struct event_header) != sizeof(u32));
 300
 301         padding = lib_ring_buffer_align(config, offset,
 302                                         sizeof(struct event_header));
 303         offset += padding;
 304         offset += sizeof(struct event_header);
 305
 306         if (unlikely(rflags)) {
 307                 switch (rflags) {
 308                 case LTT_RFLAG_ID_SIZE_TSC:
 309                         offset += sizeof(u16) + sizeof(u16);
 310                         if (data_size >= LTT_MAX_SMALL_SIZE)
 311                                 offset += sizeof(u32);
 312                         offset += ltt_align(offset, sizeof(u64));
 313                         offset += sizeof(u64);
 314                         break;
 315                 case LTT_RFLAG_ID_SIZE:
 316                         offset += sizeof(u16) + sizeof(u16);
 317                         if (data_size >= LTT_MAX_SMALL_SIZE)
 318                                 offset += sizeof(u32);
 319                         break;
 320                 case LTT_RFLAG_ID:
 321                         offset += sizeof(u16);
 322                         break;
 323                 }
 324         }
 325
 326         *pre_header_padding = padding;
 327         return offset - orig_offset;
 328 }
 329
 330 #include <linux/ringbuffer/api.h>
 331
 332 extern
 333 size_t ltt_write_event_header_slow(struct ltt_chanbuf_alloc *bufa,
 334                                    struct ltt_chan_alloc *chana,
 335                                    long buf_offset, u16 eID, u32 event_size,
 336                                    u64 tsc, unsigned int rflags);
 337
 338 /*
 339  * ltt_write_event_header
 340  *
 341  * Writes the event header to the offset (already aligned on 32-bits).
 342  *
 343  * @config: ring buffer instance configuration
 344  * @ctx: reservation context
 345  * @eID : event ID
 346  * @event_size : size of the event, excluding the event header.
 347  */
 348 static __inline__
 349 void ltt_write_event_header(const struct lib_ring_buffer_config *config,
 350                             struct lib_ring_buffer_ctx *ctx,
 351                             u16 eID, u32 event_size)
 352 {
 353         struct event_header header;
 354
 355         if (unlikely(ctx->rflags))
 356                 goto slow_path;
 357
 358         header.id_time = eID << LTT_TSC_BITS;
 359         header.id_time |= (u32)ctx->tsc & LTT_TSC_MASK;
 360         lib_ring_buffer_write(config, ctx, &header, sizeof(header));
 361
 362 slow_path:
 363         ltt_write_event_header_slow(config, ctx, eID, event_size);
 364 }
 365
 366 #if 0
 367 /*
 368  * ltt_read_event_header
 369  * buf_offset must aligned on 32 bits
 370  */
 371 static __inline__
 372 size_t ltt_read_event_header(struct ltt_chanbuf_alloc *bufa, long buf_offset,
 373                              u64 *tsc, u32 *event_size, u16 *eID,
 374                              unsigned int *rflags)
 375 {
 376         struct ltt_event_header header;
 377         u16 small_size;
 378
 379         ltt_relay_read(bufa, buf_offset, &header, sizeof(header));
 380         buf_offset += sizeof(header);
 381
 382         *event_size = INT_MAX;
 383         *eID = header.id_time >> LTT_TSC_BITS;
 384         *tsc = header.id_time & LTT_TSC_MASK;
 385
 386         switch (*eID) {
 387         case 29:
 388                 *rflags = LTT_RFLAG_ID_SIZE_TSC;
 389                 ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
 390                 buf_offset += sizeof(u16);
 391                 ltt_relay_read(bufa, buf_offset, &small_size, sizeof(u16));
 392                 buf_offset += sizeof(u16);
 393                 if (small_size == LTT_MAX_SMALL_SIZE) {
 394                         ltt_relay_read(bufa, buf_offset, event_size,
 395                                         sizeof(u32));
 396                         buf_offset += sizeof(u32);
 397                 } else
 398                         *event_size = small_size;
 399                 buf_offset += ltt_align(buf_offset, sizeof(u64));
 400                 ltt_relay_read(bufa, buf_offset, tsc, sizeof(u64));
 401                 buf_offset += sizeof(u64);
 402                 break;
 403         case 30:
 404                 *rflags = LTT_RFLAG_ID_SIZE;
 405                 ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
 406                 buf_offset += sizeof(u16);
 407                 ltt_relay_read(bufa, buf_offset, &small_size, sizeof(u16));
 408                 buf_offset += sizeof(u16);
 409                 if (small_size == LTT_MAX_SMALL_SIZE) {
 410                         ltt_relay_read(bufa, buf_offset, event_size,
 411                                         sizeof(u32));
 412                         buf_offset += sizeof(u32);
 413                 } else
 414                         *event_size = small_size;
 415                 break;
 416         case 31:
 417                 *rflags = LTT_RFLAG_ID;
 418                 ltt_relay_read(bufa, buf_offset, eID, sizeof(u16));
 419                 buf_offset += sizeof(u16);
 420                 break;
 421         default:
 422                 *rflags = 0;
 423                 break;
 424         }
 425
 426         return buf_offset;
 427 }
 428 #endif //0
 429
 430 /*
 431  * Control channels :
 432  * control/metadata
 433  * control/interrupts
 434  * control/...
 435  *
 436  * cpu channel :
 437  * cpu
 438  */
 439 #define LTT_RELAY_ROOT                  "ltt"
 440
 441 #define LTT_METADATA_CHANNEL            "metadata_state"
 442 #define LTT_FD_STATE_CHANNEL            "fd_state"
 443 #define LTT_GLOBAL_STATE_CHANNEL        "global_state"
 444 #define LTT_IRQ_STATE_CHANNEL           "irq_state"
 445 #define LTT_MODULE_STATE_CHANNEL        "module_state"
 446 #define LTT_NETIF_STATE_CHANNEL         "netif_state"
 447 #define LTT_SOFTIRQ_STATE_CHANNEL       "softirq_state"
 448 #define LTT_SWAP_STATE_CHANNEL          "swap_state"
 449 #define LTT_SYSCALL_STATE_CHANNEL       "syscall_state"
 450 #define LTT_TASK_STATE_CHANNEL          "task_state"
 451 #define LTT_VM_STATE_CHANNEL            "vm_state"
 452 #define LTT_FS_CHANNEL                  "fs"
 453 #define LTT_INPUT_CHANNEL               "input"
 454 #define LTT_IPC_CHANNEL                 "ipc"
 455 #define LTT_KERNEL_CHANNEL              "kernel"
 456 #define LTT_MM_CHANNEL                  "mm"
 457 #define LTT_RCU_CHANNEL                 "rcu"
 458
 459 #define LTT_FLIGHT_PREFIX               "flight-"
 460
 461 #define LTT_ASCII                       "ascii"
 462
 463 /* Tracer properties */
 464 #define LTT_DEFAULT_SUBBUF_SIZE_LOW     65536
 465 #define LTT_DEFAULT_N_SUBBUFS_LOW       2
 466 #define LTT_DEFAULT_SUBBUF_SIZE_MED     262144
 467 #define LTT_DEFAULT_N_SUBBUFS_MED       2
 468 #define LTT_DEFAULT_SUBBUF_SIZE_HIGH    1048576
 469 #define LTT_DEFAULT_N_SUBBUFS_HIGH      2
 470 #define LTT_TRACER_MAGIC_NUMBER         0x00D6B7ED
 471 #define LTT_TRACER_VERSION_MAJOR        2
 472 #define LTT_TRACER_VERSION_MINOR        6
 473
 474 /**
 475  * ltt_write_trace_header - Write trace header
 476  * @priv: Private data (struct trace)
 477  * @header: Memory address where the information must be written to
 478  */
 479 static __inline__
 480 void ltt_write_trace_header(void *priv,
 481                             struct subbuffer_header *header)
 482 {
 483         struct ltt_trace *trace = priv;
 484
 485         header->magic_number = LTT_TRACER_MAGIC_NUMBER;
 486         header->major_version = LTT_TRACER_VERSION_MAJOR;
 487         header->minor_version = LTT_TRACER_VERSION_MINOR;
 488         header->arch_size = sizeof(void *);
 489         header->alignment = lib_ring_buffer_get_alignment();
 490         header->start_time_sec = trace->start_time.tv_sec;
 491         header->start_time_usec = trace->start_time.tv_usec;
 492         header->start_freq = trace->start_freq;
 493         header->freq_scale = trace->freq_scale;
 494 }
 495
 496 /*
 497  * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
 498  * nearly full buffer. User space won't use this last amount of space when in
 499  * blocking mode. This space also includes the event header that would be
 500  * written by this user space event.
 501  */
 502 #define LTT_RESERVE_CRITICAL            4096
 503
 504 /* Register and unregister function pointers */
 505
 506 enum ltt_module_function {
 507         LTT_FUNCTION_RUN_FILTER,
 508         LTT_FUNCTION_FILTER_CONTROL,
 509         LTT_FUNCTION_STATEDUMP
 510 };
 511
 512 extern int ltt_module_register(enum ltt_module_function name, void *function,
 513                                struct module *owner);
 514 extern void ltt_module_unregister(enum ltt_module_function name);
 515
 516 void ltt_transport_register(struct ltt_transport *transport);
 517 void ltt_transport_unregister(struct ltt_transport *transport);
 518
 519 /* Exported control function */
 520
 521 enum ltt_control_msg {
 522         LTT_CONTROL_START,
 523         LTT_CONTROL_STOP,
 524         LTT_CONTROL_CREATE_TRACE,
 525         LTT_CONTROL_DESTROY_TRACE
 526 };
 527
 528 union ltt_control_args {
 529         struct {
 530                 enum trace_mode mode;
 531                 unsigned int subbuf_size_low;
 532                 unsigned int n_subbufs_low;
 533                 unsigned int subbuf_size_med;
 534                 unsigned int n_subbufs_med;
 535                 unsigned int subbuf_size_high;
 536                 unsigned int n_subbufs_high;
 537         } new_trace;
 538 };
 539
 540 int _ltt_trace_setup(const char *trace_name);
 541 int ltt_trace_setup(const char *trace_name);
 542 struct ltt_trace *_ltt_trace_find_setup(const char *trace_name);
 543 int ltt_trace_set_type(const char *trace_name, const char *trace_type);
 544 int ltt_trace_set_channel_subbufsize(const char *trace_name,
 545                                      const char *channel_name,
 546                                      unsigned int size);
 547 int ltt_trace_set_channel_subbufcount(const char *trace_name,
 548                                       const char *channel_name,
 549                                       unsigned int cnt);
 550 int ltt_trace_set_channel_switch_timer(const char *trace_name,
 551                                        const char *channel_name,
 552                                        unsigned long interval);
 553 int ltt_trace_set_channel_overwrite(const char *trace_name,
 554                                     const char *channel_name,
 555                                     unsigned int overwrite);
 556 int ltt_trace_alloc(const char *trace_name);
 557 int ltt_trace_destroy(const char *trace_name);
 558 int ltt_trace_start(const char *trace_name);
 559 int ltt_trace_stop(const char *trace_name);
 560
 561 extern int ltt_control(enum ltt_control_msg msg, const char *trace_name,
 562                        const char *trace_type, union ltt_control_args args);
 563
 564 enum ltt_filter_control_msg {
 565         LTT_FILTER_DEFAULT_ACCEPT,
 566         LTT_FILTER_DEFAULT_REJECT
 567 };
 568
 569 extern int ltt_filter_control(enum ltt_filter_control_msg msg,
 570                               const char *trace_name);
 571
 572 extern struct dentry *get_filter_root(void);
 573
 574 void ltt_core_register(int (*function)(u8, void *));
 575
 576 void ltt_core_unregister(void);
 577
 578 void ltt_release_trace(struct kref *kref);
 579 void ltt_release_transport(struct kref *kref);
 580
 581 extern int ltt_probe_register(struct ltt_available_probe *pdata);
 582 extern int ltt_probe_unregister(struct ltt_available_probe *pdata);
 583 extern int ltt_marker_connect(const char *channel, const char *mname,
 584                               const char *pname);
 585 extern int ltt_marker_disconnect(const char *channel, const char *mname,
 586                                  const char *pname);
 587 extern void ltt_dump_marker_state(struct ltt_trace *trace);
 588
 589 void ltt_lock_traces(void);
 590 void ltt_unlock_traces(void);
 591
 592 extern int ltt_ascii_create_dir(struct ltt_trace *new_trace);
 593 extern void ltt_ascii_remove_dir(struct ltt_trace *trace);
 594 extern int ltt_ascii_create(struct ltt_chan *chan);
 595 extern void ltt_ascii_remove(struct ltt_chan *chan);
 596
 597 extern
 598 void ltt_statedump_register_kprobes_dump(void (*callback)(void *call_data));
 599 extern
 600 void ltt_statedump_unregister_kprobes_dump(void (*callback)(void *call_data));
 601
 602 extern void ltt_dump_softirq_vec(void *call_data);
 603
 604 #ifdef CONFIG_HAVE_LTT_DUMP_TABLES
 605 extern void ltt_dump_sys_call_table(void *call_data);
 606 extern void ltt_dump_idt_table(void *call_data);
 607 #else
 608 static inline void ltt_dump_sys_call_table(void *call_data)
 609 {
 610 }
 611
 612 static inline void ltt_dump_idt_table(void *call_data)
 613 {
 614 }
 615 #endif
 616
 617 #endif /* _LTT_TRACER_H */