instrumentation/events/lttng-module/rcu.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 #undef TRACE_SYSTEM
   3 #define TRACE_SYSTEM rcu
   4
   5 #if !defined(LTTNG_TRACE_RCU_H) || defined(TRACE_HEADER_MULTI_READ)
   6 #define LTTNG_TRACE_RCU_H
   7
   8 #include <probes/lttng-tracepoint-event.h>
   9
  10 /*
  11  * Tracepoint for start/end markers used for utilization calculations.
  12  * By convention, the string is of the following forms:
  13  *
  14  * "Start <activity>" -- Mark the start of the specified activity,
  15  *                       such as "context switch".  Nesting is permitted.
  16  * "End <activity>" -- Mark the end of the specified activity.
  17  *
  18  * An "@" character within "<activity>" is a comment character: Data
  19  * reduction scripts will ignore the "@" and the remainder of the line.
  20  */
  21 LTTNG_TRACEPOINT_EVENT(rcu_utilization,
  22
  23         TP_PROTO(const char *s),
  24
  25         TP_ARGS(s),
  26
  27         TP_FIELDS(
  28                 ctf_string(s, s)
  29         )
  30 )
  31
  32 #ifdef CONFIG_RCU_TRACE
  33
  34 #if defined(CONFIG_TREE_RCU)
  35
  36 /*
  37  * Tracepoint for grace-period events: starting and ending a grace
  38  * period ("start" and "end", respectively), a CPU noting the start
  39  * of a new grace period or the end of an old grace period ("cpustart"
  40  * and "cpuend", respectively), a CPU passing through a quiescent
  41  * state ("cpuqs"), a CPU coming online or going offline ("cpuonl"
  42  * and "cpuofl", respectively), and a CPU being kicked for being too
  43  * long in dyntick-idle mode ("kick").
  44  */
  45 LTTNG_TRACEPOINT_EVENT(rcu_grace_period,
  46
  47         TP_PROTO(const char *rcuname, unsigned long gp_seq, const char *gpevent),
  48
  49         TP_ARGS(rcuname, gp_seq, gpevent),
  50
  51         TP_FIELDS(
  52                 ctf_string(rcuname, rcuname)
  53                 ctf_integer(unsigned long, gp_seq, gp_seq)
  54                 ctf_string(gpevent, gpevent)
  55         )
  56 )
  57
  58 /*
  59  * Tracepoint for grace-period-initialization events.  These are
  60  * distinguished by the type of RCU, the new grace-period number, the
  61  * rcu_node structure level, the starting and ending CPU covered by the
  62  * rcu_node structure, and the mask of CPUs that will be waited for.
  63  * All but the type of RCU are extracted from the rcu_node structure.
  64  */
  65 LTTNG_TRACEPOINT_EVENT(rcu_grace_period_init,
  66
  67         TP_PROTO(const char *rcuname, unsigned long gp_seq, u8 level,
  68                  int grplo, int grphi, unsigned long qsmask),
  69
  70         TP_ARGS(rcuname, gp_seq, level, grplo, grphi, qsmask),
  71
  72         TP_FIELDS(
  73                 ctf_string(rcuname, rcuname)
  74                 ctf_integer(unsigned long, gp_seq, gp_seq)
  75                 ctf_integer(u8, level, level)
  76                 ctf_integer(int, grplo, grplo)
  77                 ctf_integer(int, grphi, grphi)
  78                 ctf_integer(unsigned long, qsmask, qsmask)
  79         )
  80 )
  81
  82 /*
  83  * Tracepoint for tasks blocking within preemptible-RCU read-side
  84  * critical sections.  Track the type of RCU (which one day might
  85  * include SRCU), the grace-period number that the task is blocking
  86  * (the current or the next), and the task's PID.
  87  */
  88 LTTNG_TRACEPOINT_EVENT(rcu_preempt_task,
  89
  90         TP_PROTO(const char *rcuname, int pid, unsigned long gp_seq),
  91
  92         TP_ARGS(rcuname, pid, gp_seq),
  93
  94         TP_FIELDS(
  95                 ctf_string(rcuname, rcuname)
  96                 ctf_integer(unsigned long, gp_seq, gp_seq)
  97                 ctf_integer(int, pid, pid)
  98         )
  99 )
 100
 101 /*
 102  * Tracepoint for tasks that blocked within a given preemptible-RCU
 103  * read-side critical section exiting that critical section.  Track the
 104  * type of RCU (which one day might include SRCU) and the task's PID.
 105  */
 106 LTTNG_TRACEPOINT_EVENT(rcu_unlock_preempted_task,
 107
 108         TP_PROTO(const char *rcuname, unsigned long gp_seq, int pid),
 109
 110         TP_ARGS(rcuname, gp_seq, pid),
 111
 112         TP_FIELDS(
 113                 ctf_string(rcuname, rcuname)
 114                 ctf_integer(unsigned long, gp_seq, gp_seq)
 115                 ctf_integer(int, pid, pid)
 116         )
 117 )
 118
 119 /*
 120  * Tracepoint for quiescent-state-reporting events.  These are
 121  * distinguished by the type of RCU, the grace-period number, the
 122  * mask of quiescent lower-level entities, the rcu_node structure level,
 123  * the starting and ending CPU covered by the rcu_node structure, and
 124  * whether there are any blocked tasks blocking the current grace period.
 125  * All but the type of RCU are extracted from the rcu_node structure.
 126  */
 127 LTTNG_TRACEPOINT_EVENT(rcu_quiescent_state_report,
 128
 129         TP_PROTO(const char *rcuname, unsigned long gp_seq,
 130                  unsigned long mask, unsigned long qsmask,
 131                  u8 level, int grplo, int grphi, int gp_tasks),
 132
 133         TP_ARGS(rcuname, gp_seq, mask, qsmask, level, grplo, grphi, gp_tasks),
 134
 135         TP_FIELDS(
 136                 ctf_string(rcuname, rcuname)
 137                 ctf_integer(unsigned long, gp_seq, gp_seq)
 138                 ctf_integer(unsigned long, mask, mask)
 139                 ctf_integer(unsigned long, qsmask, qsmask)
 140                 ctf_integer(u8, level, level)
 141                 ctf_integer(int, grplo, grplo)
 142                 ctf_integer(int, grphi, grphi)
 143                 ctf_integer(u8, gp_tasks, gp_tasks)
 144         )
 145 )
 146
 147 /*
 148  * Tracepoint for quiescent states detected by force_quiescent_state().
 149  * These trace events include the type of RCU, the grace-period number
 150  * that was blocked by the CPU, the CPU itself, and the type of quiescent
 151  * state, which can be "dti" for dyntick-idle mode, "ofl" for CPU offline,
 152  * or "kick" when kicking a CPU that has been in dyntick-idle mode for
 153  * too long.
 154  */
 155 LTTNG_TRACEPOINT_EVENT(rcu_fqs,
 156
 157         TP_PROTO(const char *rcuname, unsigned long gp_seq, int cpu, const char *qsevent),
 158
 159         TP_ARGS(rcuname, gp_seq, cpu, qsevent),
 160
 161         TP_FIELDS(
 162                 ctf_integer(unsigned long, gp_seq, gp_seq)
 163                 ctf_integer(int, cpu, cpu)
 164                 ctf_string(rcuname, rcuname)
 165                 ctf_string(qsevent, qsevent)
 166         )
 167 )
 168
 169 #endif
 170
 171 /*
 172  * Tracepoint for dyntick-idle entry/exit events.  These take a string
 173  * as argument: "Start" for entering dyntick-idle mode, "End" for
 174  * leaving it, "--=" for events moving towards idle, and "++=" for events
 175  * moving away from idle.  "Error on entry: not idle task" and "Error on
 176  * exit: not idle task" indicate that a non-idle task is erroneously
 177  * toying with the idle loop.
 178  *
 179  * These events also take a pair of numbers, which indicate the nesting
 180  * depth before and after the event of interest.  Note that task-related
 181  * events use the upper bits of each number, while interrupt-related
 182  * events use the lower bits.
 183  */
 184 LTTNG_TRACEPOINT_EVENT(rcu_dyntick,
 185
 186         TP_PROTO(const char *polarity, long oldnesting, long newnesting, int dynticks),
 187
 188         TP_ARGS(polarity, oldnesting, newnesting, dynticks),
 189
 190         TP_FIELDS(
 191                 ctf_string(polarity, polarity)
 192                 ctf_integer(long, oldnesting, oldnesting)
 193                 ctf_integer(long, newnesting, newnesting)
 194                 ctf_integer(int, dynticks, dynticks)
 195         )
 196 )
 197
 198 /*
 199  * Tracepoint for RCU preparation for idle, the goal being to get RCU
 200  * processing done so that the current CPU can shut off its scheduling
 201  * clock and enter dyntick-idle mode.  One way to accomplish this is
 202  * to drain all RCU callbacks from this CPU, and the other is to have
 203  * done everything RCU requires for the current grace period.  In this
 204  * latter case, the CPU will be awakened at the end of the current grace
 205  * period in order to process the remainder of its callbacks.
 206  *
 207  * These tracepoints take a string as argument:
 208  *
 209  *      "No callbacks": Nothing to do, no callbacks on this CPU.
 210  *      "In holdoff": Nothing to do, holding off after unsuccessful attempt.
 211  *      "Begin holdoff": Attempt failed, don't retry until next jiffy.
 212  *      "Dyntick with callbacks": Entering dyntick-idle despite callbacks.
 213  *      "Dyntick with lazy callbacks": Entering dyntick-idle w/lazy callbacks.
 214  *      "More callbacks": Still more callbacks, try again to clear them out.
 215  *      "Callbacks drained": All callbacks processed, off to dyntick idle!
 216  *      "Timer": Timer fired to cause CPU to continue processing callbacks.
 217  *      "Demigrate": Timer fired on wrong CPU, woke up correct CPU.
 218  *      "Cleanup after idle": Idle exited, timer canceled.
 219  */
 220 LTTNG_TRACEPOINT_EVENT(rcu_prep_idle,
 221
 222         TP_PROTO(const char *reason),
 223
 224         TP_ARGS(reason),
 225
 226         TP_FIELDS(
 227                 ctf_string(reason, reason)
 228         )
 229 )
 230
 231 /*
 232  * Tracepoint for the registration of a single RCU callback function.
 233  * The first argument is the type of RCU, the second argument is
 234  * a pointer to the RCU callback itself, the third element is the
 235  * number of lazy callbacks queued, and the fourth element is the
 236  * total number of callbacks queued.
 237  */
 238 LTTNG_TRACEPOINT_EVENT(rcu_callback,
 239
 240         TP_PROTO(const char *rcuname, struct rcu_head *rhp, long qlen),
 241
 242         TP_ARGS(rcuname, rhp, qlen),
 243
 244         TP_FIELDS(
 245                 ctf_string(rcuname, rcuname)
 246                 ctf_integer_hex(void *, rhp, rhp)
 247                 ctf_integer_hex(void *, func, rhp->func)
 248                 ctf_integer(long, qlen, qlen)
 249         )
 250 )
 251
 252 /*
 253  * Tracepoint for the registration of a single RCU callback of the special
 254  * kfree() form.  The first argument is the RCU type, the second argument
 255  * is a pointer to the RCU callback, the third argument is the offset
 256  * of the callback within the enclosing RCU-protected data structure,
 257  * the fourth argument is the number of lazy callbacks queued, and the
 258  * fifth argument is the total number of callbacks queued.
 259  */
 260 LTTNG_TRACEPOINT_EVENT(rcu_kfree_callback,
 261
 262         TP_PROTO(const char *rcuname, struct rcu_head *rhp, unsigned long offset,
 263                  long qlen),
 264
 265         TP_ARGS(rcuname, rhp, offset, qlen),
 266
 267         TP_FIELDS(
 268                 ctf_string(rcuname, rcuname)
 269                 ctf_integer_hex(void *, rhp, rhp)
 270                 ctf_integer_hex(unsigned long, offset, offset)
 271                 ctf_integer(long, qlen, qlen)
 272         )
 273 )
 274
 275 /*
 276  * Tracepoint for marking the beginning rcu_do_batch, performed to start
 277  * RCU callback invocation.  The first argument is the RCU flavor,
 278  * the second is the number of lazy callbacks queued, the third is
 279  * the total number of callbacks queued, and the fourth argument is
 280  * the current RCU-callback batch limit.
 281  */
 282 LTTNG_TRACEPOINT_EVENT(rcu_batch_start,
 283
 284         TP_PROTO(const char *rcuname, long qlen, long blimit),
 285
 286         TP_ARGS(rcuname, qlen, blimit),
 287
 288         TP_FIELDS(
 289                 ctf_string(rcuname, rcuname)
 290                 ctf_integer(long, qlen, qlen)
 291                 ctf_integer(long, blimit, blimit)
 292         )
 293 )
 294
 295 /*
 296  * Tracepoint for the invocation of a single RCU callback function.
 297  * The first argument is the type of RCU, and the second argument is
 298  * a pointer to the RCU callback itself.
 299  */
 300 LTTNG_TRACEPOINT_EVENT(rcu_invoke_callback,
 301
 302         TP_PROTO(const char *rcuname, struct rcu_head *rhp),
 303
 304         TP_ARGS(rcuname, rhp),
 305
 306         TP_FIELDS(
 307                 ctf_string(rcuname, rcuname)
 308                 ctf_integer_hex(void *, rhp, rhp)
 309                 ctf_integer_hex(void *, func, rhp->func)
 310         )
 311 )
 312
 313 /*
 314  * Tracepoint for the invocation of a single RCU callback of the special
 315  * kfree() form.  The first argument is the RCU flavor, the second
 316  * argument is a pointer to the RCU callback, and the third argument
 317  * is the offset of the callback within the enclosing RCU-protected
 318  * data structure.
 319  */
 320 LTTNG_TRACEPOINT_EVENT(rcu_invoke_kfree_callback,
 321
 322         TP_PROTO(const char *rcuname, struct rcu_head *rhp, unsigned long offset),
 323
 324         TP_ARGS(rcuname, rhp, offset),
 325
 326         TP_FIELDS(
 327                 ctf_string(rcuname, rcuname)
 328                 ctf_integer_hex(void *, rhp, rhp)
 329                 ctf_integer(unsigned long, offset, offset)
 330         )
 331 )
 332
 333 /*
 334  * Tracepoint for exiting rcu_do_batch after RCU callbacks have been
 335  * invoked.  The first argument is the name of the RCU flavor,
 336  * the second argument is number of callbacks actually invoked,
 337  * the third argument (cb) is whether or not any of the callbacks that
 338  * were ready to invoke at the beginning of this batch are still
 339  * queued, the fourth argument (nr) is the return value of need_resched(),
 340  * the fifth argument (iit) is 1 if the current task is the idle task,
 341  * and the sixth argument (risk) is the return value from
 342  * rcu_is_callbacks_kthread().
 343  */
 344 LTTNG_TRACEPOINT_EVENT(rcu_batch_end,
 345
 346         TP_PROTO(const char *rcuname, int callbacks_invoked,
 347                  char cb, char nr, char iit, char risk),
 348
 349         TP_ARGS(rcuname, callbacks_invoked, cb, nr, iit, risk),
 350
 351         TP_FIELDS(
 352                 ctf_string(rcuname, rcuname)
 353                 ctf_integer(int, callbacks_invoked, callbacks_invoked)
 354                 ctf_integer(char, cb, cb)
 355                 ctf_integer(char, nr, nr)
 356                 ctf_integer(char, iit, iit)
 357                 ctf_integer(char, risk, risk)
 358         )
 359 )
 360
 361 /*
 362  * Tracepoint for rcutorture readers.  The first argument is the name
 363  * of the RCU flavor from rcutorture's viewpoint and the second argument
 364  * is the callback address.
 365  */
 366 LTTNG_TRACEPOINT_EVENT(rcu_torture_read,
 367
 368         TP_PROTO(const char *rcutorturename, struct rcu_head *rhp,
 369                  unsigned long secs, unsigned long c_old, unsigned long c),
 370
 371         TP_ARGS(rcutorturename, rhp, secs, c_old, c),
 372
 373         TP_FIELDS(
 374                 ctf_string(rcutorturename, rcutorturename)
 375                 ctf_integer_hex(struct rcu_head *, rhp, rhp)
 376                 ctf_integer(unsigned long, secs, secs)
 377                 ctf_integer(unsigned long, c_old, c_old)
 378                 ctf_integer(unsigned long, c, c)
 379         )
 380 )
 381
 382 /*
 383  * Tracepoint for _rcu_barrier() execution.  The string "s" describes
 384  * the _rcu_barrier phase:
 385  *      "Begin": rcu_barrier_callback() started.
 386  *      "Check": rcu_barrier_callback() checking for piggybacking.
 387  *      "EarlyExit": rcu_barrier_callback() piggybacked, thus early exit.
 388  *      "Inc1": rcu_barrier_callback() piggyback check counter incremented.
 389  *      "Offline": rcu_barrier_callback() found offline CPU
 390  *      "OnlineQ": rcu_barrier_callback() found online CPU with callbacks.
 391  *      "OnlineNQ": rcu_barrier_callback() found online CPU, no callbacks.
 392  *      "IRQ": An rcu_barrier_callback() callback posted on remote CPU.
 393  *      "CB": An rcu_barrier_callback() invoked a callback, not the last.
 394  *      "LastCB": An rcu_barrier_callback() invoked the last callback.
 395  *      "Inc2": rcu_barrier_callback() piggyback check counter incremented.
 396  * The "cpu" argument is the CPU or -1 if meaningless, the "cnt" argument
 397  * is the count of remaining callbacks, and "done" is the piggybacking count.
 398  */
 399 LTTNG_TRACEPOINT_EVENT(rcu_barrier,
 400
 401         TP_PROTO(const char *rcuname, const char *s, int cpu, int cnt, unsigned long done),
 402
 403         TP_ARGS(rcuname, s, cpu, cnt, done),
 404
 405         TP_FIELDS(
 406                 ctf_string(rcuname, rcuname)
 407                 ctf_string(s, s)
 408                 ctf_integer(int, cpu, cpu)
 409                 ctf_integer(int, cnt, cnt)
 410                 ctf_integer(unsigned long, done, done)
 411         )
 412 )
 413
 414 #else /* #ifdef CONFIG_RCU_TRACE */
 415
 416 #define trace_rcu_grace_period(rcuname, gp_seq, gpevent) do { } while (0)
 417 #define trace_rcu_grace_period_init(rcuname, gp_seq, level, grplo, grphi, \
 418                                     qsmask) do { } while (0)
 419 #define trace_rcu_preempt_task(rcuname, pid, gp_seq) do { } while (0)
 420 #define trace_rcu_unlock_preempted_task(rcuname, gp_seq, pid) do { } while (0)
 421 #define trace_rcu_quiescent_state_report(rcuname, gp_seq, mask, qsmask, level, \
 422                                          grplo, grphi, gp_tasks) do { } \
 423         while (0)
 424 #define trace_rcu_fqs(rcuname, gp_seq, cpu, qsevent) do { } while (0)
 425
 426 #define trace_rcu_dyntick(polarity, oldnesting, newnesting, dyntick) do { } while (0)
 427 #define trace_rcu_prep_idle(reason) do { } while (0)
 428 #define trace_rcu_callback(rcuname, rhp, qlen_lazy, qlen) do { } while (0)
 429 #define trace_rcu_kfree_callback(rcuname, rhp, offset, qlen_lazy, qlen) \
 430         do { } while (0)
 431 #define trace_rcu_batch_start(rcuname, qlen_lazy, qlen, blimit) \
 432         do { } while (0)
 433 #define trace_rcu_invoke_callback(rcuname, rhp) do { } while (0)
 434 #define trace_rcu_invoke_kfree_callback(rcuname, rhp, offset) do { } while (0)
 435 #define trace_rcu_batch_end(rcuname, callbacks_invoked, cb, nr, iit, risk) \
 436         do { } while (0)
 437 #define trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
 438         do { } while (0)
 439 #define trace_rcu_barrier(name, s, cpu, cnt, done) do { } while (0)
 440 #endif /* #else #ifdef CONFIG_RCU_TRACE */
 441
 442 #endif /* LTTNG_TRACE_RCU_H */
 443
 444 /* This part must be outside protection */
 445 #include <probes/define_trace.h>